TVA
v>EPA
Tennessee Valley
Authority
Division of Energy Demonstrations
and Technology
Chattanooga, Tennessee 37401
EOT 109
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-80-100
May 1980
Processing Sludge:
Sludge Characterization
Studies
Interagency
Energy/Environment
R&D Program Report
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EPA-600/7-80-100
May 1980
Processing Sludge: Sludge
Characterization Studies
by
J.L. Crowe (TVA-Chattanooga)
and S.K. Seale (TVA-Muscle Shoals)
Tennessee Valley Authority
Division of Energy Demonstrations and Technology
Chattanooga, Tennessee 47401
EPA Interagency Agreement No: D5-0721
Program Element No. EHE624A
EPA Project Officer: Julian W. Jones
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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DISCLAIMER
This report was prepared by the Tennessee Valley Authority and has
been reviewed by the Office of Energy, Minerals, and Industry, U.S.
Environmental Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the views and poli-
cies of the Tennessee Valley Authority, nor does mention of trade names
or commercial products constitute endorsement or recommendation for use.
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ABSTRACT
This report summarizes work completed during the period March 13,
1975, to June 30, 1977. The main emphasis of this work was to determine
the range of variability of the solids from scrubbers operated at the
Shawnee test facility and to attempt to correlate this variability with
plant operating conditions. Slurry and solids characterization studies
were conducted on 167 samples obtained from the turbulent contact absorber
(TCA) and venturi-spray tower scrubbing systems.
Systems operating with limestone as the absorbent precipitate
CaSOs*0.5H20 primarily as single plates and relatively flat rosette forms,
while spheroidal aggregates of many small plate crystals are formed when
lime is used. The form of sulfite morphology observed is shown to be
independent of scrubber configuration. Clear evidence is seen of the
relationship between the crystal size (in limestone systems) and system
Ca:S ratio (stoichiometry), although no such relationship is observed in
lime systems. The difference in sulfite crystal morphology observed
between lime and limestone systems is attributed to precipitation and
crystal growth rates. When forced oxidation is used with either absorbent,
the reaction product is seen to consist of very large, blocky CaS04*2H20
crystals; no CaSOg'0.5^0 forms are seen.
A simple and rapid method for the determination of gypsum in scrubber
solids (over the range 0.1 to 10.0 wt. percent) was developed. The peak
area resulting from gypsum dehydration (using differential scanning colori-
metry) is directly and linearly proportional to the concentration of gypsum
in a sample. This peak is not obscured or interfered with by other compon-
ents in the sample matrices and thus provides a clear distinction between
gypsum SQ~4 and substituted 804 .
Statistical analysis of the venturi-spray tower data resulted in
regression models which characterize the percent settled solids and per-
cent bulk density as a nonlinear function of calcium sulfite solids and
the percent solids recirculated. Behavior of the solids produced by both
lime and limestone systems are summarized for low and high levels of
oxidation.
High levels of settled solids (50 percent or more) for both the lime
and limestone product sludges are associated with high oxidation, high
percentage solids recirculated, high fly ash content, and low sulfite
solids. Low percentages of settled solids (35 percent or less) for both
systems occur with low levels of solids recirculated, average oxidation,
low fly ash content, and high levels of carbonate.
High levels of settled bulk density, for lime and limestone product
sludges, of 1.4 g/cc or more are characterized by high oxidation, high
levels of solids recirculated, high fly ash content, and low sulfite solids.
As a contrast, low fly ash content, high percentages of sulfite and car-
bonate, and solids recirculated plus low oxidation are noted for settled
bulk densities of 1.2 g/cc or less.
111
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CONTENTS
age
Disclaimer ii
Abstract iii
Figures v
Tables vii
Acknowledgements viii
Section
1 Introduction 1
2 Conclusions and Recommendations 2
3 Instrumental Techniques of Characterization 4
4 Solids Morphology 5
Sulfite Morphology 5
Morphology of Accessory Components 8
Morphology of of Solids Formed Under
Forced Oxidation 8
5 Slurry Settling Behavior 10
6 Solids Surface Area Measurements 14
7 Thermal Analysis of Scrubber Solids 15
8 Statistical Analysis 17
Mean Values 17
Percent Settled Solids 17
Settled Bulk Density 18
Relationships Found in the Data Using
Regression Analysis 19
Regression Models - Statistical
Considerations 20
9 References 22
IV
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FIGURES
Number Page
1 Photomicrographs illustrating various forms in which
CaS03-0.5H20 is found in scrubber sludge 22
2 Photomicrographs of CaSOs-O.SHgO aggregates formed
when lime is used as the absorbent 24
3 Photomicrographs of CaSOs'O.SH^O plates formed when
limestone is used as the absorbent 26
4 Photomicrographs of CaSC>3'0.5H20 aggregates formed
when lime is used as the absorbent 28
5 Photomicrographs of CaS03'0.5H20 plates formed when
limestone is used as the absorbent 30
6 Photomicrographs of CaS03'0.5H20 aggregates formed
when using lime as the absorbent 32
7 Photomicrographs illustrating the relationship
between CaSOs'O.Sl^O plate size and scrubber system
Ca:S stoichiometry with limestone as the absorbent . . 34
8 Photomicrographs of "Mixed Crystals" forms 36
9 High-magnification photomicrographs of sulfite-gypsum
"Mixed Crystals" forms 38
10 Photomicrographs of sludge solids components with
and without forced oxidation on the same system
(venturi/spray tower) 40
11 Slurry settling rate curves 43
12 Photomicrographs of solids producing settling
behavior shown in Figures 11B 44
13 Settling rate of lime and limestone scrubber
slurries 46
14 Settled bulk density for lime and limestone scrubber
slurries 47
15 Distribution of settled solids content values for
solids produced under lime, limestone, and fly ash-
free operation 48
16 Distribution of surface area values for solids
produced under lime, limestone, and fly ash-
free operation 49
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FIGURES
(Continued)
Number
17 Thermograms for lime and limestone-product sludge. . . 50
18 Final settled solids content of limestone scrubber
slurries as a function of sulfite content 51
19 Final settled solids content of limestone scrubber
slurries as a function of recirculated solids 52
20 Perdicted and observed final settled solids content
for limestone scrubber slurries 53
21 Settled bulk density of limestone scrubber slurries
as a function of sulfite content 54
22 Settled bulk density of limestone slurries as a
function of recirculated solids content 55
23 Predicted and observed settled bulk density for
limestone scrubber slurries 56
24 Final settled solids content of lime scrubber slurries
as a function of sulfite content 57
25 Final settled solids content of lime scrubber slurries
as a function of recirculated solids content 58
26 Predicted and observed final settled solids content
for lime scrubber slurries 59
27 Settled bulk density of lime scrubber slurries as a
function of sulfite content 60
28 Settled bulk density of lime slurries as a function
of recirculated solids content 61
29 Predicted and observed settled bulk density for lime
scrubber slurries 62
VI
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TABLES
Number Page
1 TCA Slurry Analyses 63
2 Venturi/Spray Tower Analyses 70
3 Settling Rate Determinations 77
4 Temperature of Dehydration of CaS03-0.5H20
In Dried Scrubber Solids 78
5 Analytical Results for Gypsum Determination by DSC . . 79
6 Analytical Results for the Venturi/Spray Tower
Sludge Data 79
7 Mean Values for High Settled Solids 80
8 Mean Values for Low Settled Solids 80
9 Mean Values for High Settled Bulk Density 81
10 Mean Values for Low Settled Bulk Density 81
11 Predicted Response for Changes in Variables--
Limestone System 81
12 Coefficients and Standard Errors from
Regression Analysis 82
13 Evaluation Statistics from Regression Analysis .... 82
VI1
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ACKNOWLEDGEMENTS
This study was initiated by TVA as part of the project entitled
"Processing Sludges from Lime/Limestone Wet Scrubbing Processes for
Disposal or Recycle and Studying Disposal of Fluidized Bed Combustion
Waste Products," and is supported under Federal Interagency Agreement
Numbers EPA-IAG-D7-0721 and TV-41967A between TVA and EPA for energy-
related environmental research. Thanks are extended to EPA project
officers, Dr. Theodore G. Brna, Julian W. Jones, Michael C. Osborne, and
John E. Williams. Appreciation is also extended to Chris Gottschalk,
R. A. Hiltunen, G. H. McClellan, and S. K. Seale.
VI11
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Section 1
INTRODUCTION
Sludges produced by flue gas desulfurization processes have been
extensively characterized both chemically and physically in the past, but
usually this type of study has been only of short duration, not defining
the total range of variability of the solids or relating any of the char-
acteristics to scrubber operation. With the increasing use of sludge
treatment processes, this lack of research in solid characterization pre-
sents problems when designing such systems for economy and efficiency of
operation, since the chemical and physical makeup of the sludges directly
impacts the handling and disposal requirements.
One of the purposes of this study has been to provide a long-term,
comprehensive chemical and physical characterization of lime and lime-
stone scrubbing sludges produced at the Shawnee Test Facility. Where
possible, a collateral goal has been to relate sludge properties such as
settling rate and final (settled) bulk density and solids content to pro-
cess operating conditions such as initial sludge solids content, hold
tank residence time, system Ca:S stoichiometry, presence of fly ash, sludge
pH or temperature, liquor chemistry, etc. This study also has included
investigations on the conditions of optimum crystal growth because of the
significance of this factor on pond site dewatering, filtration rates, and
liquid entrainment in the solids.
This report presents all data collected on samples taken from the
turbulent contact absorber (TCA) and venturi/spray tower systems over the
period of study March 13, 1975, to June 30, 1977.
This investigation has used comparative optical and electronic micros-
copy, x-ray diffraction, infrared spectrophotometry, and thermal analysis
to provide a comprehensive study of the range of variability observed in
sludge phases from the Shawnee scrubbers. Settling rates and determina-
tions of the final solids content and bulk densities provide data on the
physical properties of sludges.
Statistical analysis of the venturi/spray tower data resulted in
regression models which characterize the percent settled solids and per-
cent bulk density as a nonlinear function of calcium sulfite solids and
the percent solids recirculated. Behavior of the solids produced by both
lime and limestone systems are summarized for low and high levels of
oxidation.
A simple and rapid method for the quantitative determination of gypsum
in scrubber solids (over the range 0.1 to 10.Q wt. percent) was developed.
This method differentiates between gypsum S04 and substituted S04 .
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Section 2
CONCLUSIONS AND RECOMMENDATIONS
Solids produced by the TCA and venturi/spray tower at the Shawnee
Test Facility from March 13, 1975, to June 30, 1977, have been character-
ized chemically and physically. It has been shown that the primary sludge
component affecting handling and disposal is CaSOa'O.SHgO and that the
form in which this compound is precipitated is an important factor. Sys-
tems operating with limestone as the absorbent precipitate the CaSOa'O.SH^
primarily as single plates and relatively flat rosett forms, while spheroi
dal aggregates of many small plate crystals are formed when lime is used.
The form of sulfite morphology observed is shown to be independent of
scrubber configuration. In limestone systems, SEM photomicrographs docu-
ment an inverse relationship between the crystal si2e and system Ca:S
stoichiometry. No such relationship is observed in lime systems. The
difference in sulfite crystal morphology observed between lime and lime-
stone systems is attributed to precipitation and crystal growth rates.
When forced oxidation is used with either absorbent, the reaction product
is seen to consist of very large, blocky CaS04*2H20 crystals; no
forms are seen.
Sludges produced by both lime and limestone systems are shown to
display zone settling characteristics in the region above an artificial
lower limit of 10 to 12 percent solids; here, settling rates are seen
primarily to be a function of initial sludge solids content, although
solids morphology effects are seen. At initial sludge solids contents of
10 percent or less, it is seen that clarification settling applies and
that lime slurries settle faster. When forced oxidation is used with the
precipitation of large gypsum crystals, settling rates are shown to be
five to ten times faster than normal lime- or limestone-produced slurries
in the same range of solids content. Gypsum slurries are shown to settle
to a much higher final solids content than either lime- or limestone-
derived slurries. In lime and limestone systems, there are indications
that the presence of fly ash causes an increase in final (settled) solids
content. While in this study lime and limestone slurries are shown to
retain approximately the same final solids content after static settling
in a closed cylinder, other evidence is provided that shows lime slurries
dewater with more difficulty because of the generally higher surface area
of their solids components .
Thermal analysis of the dried slurry solids shows that the thermal
desolvation of the CaSOs'O.SI^O component is complex, lending support to
the suggestion th,at this component may be substituted to varying degrees
with 804" or C0^~ • The range of variability observed in measurements of
this compound's crystallographic properties also supports this premise,
although attempts to show correlations between the temperature of desol-
vation and crystallographic parameters were unsuccessful.
A simple and rapid method for the quantitative determination of gyp-
sum in scrubber solids was developed. Thermal analysis of dried scrubber
solids was employed using differential scanning colorimetry. It was shown
that the peak area resulting from gypsum dehydration is directly and
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linearly proportional to the gypsum concentration in the scrubber solids.
This peak is not obscured or interfered with by other components in the
solids matrices_and thus provides a distinction between gypsum 864 and
substituted S04 . Over the range if 0.3 to 10 percent gypsum, determina-
tion may be made with a precision of better than 5 percent and an accuracy
of better than 5 percent.
Through statistical analysis of sludge data, it was shown that high
levels of settled solids (50 percent or more) for both the lime and lime-
stone product sludges are associated with high oxidation, high percentage
solids recirculated, high fly ash content, and low sulfite solids. Low
percentages of settled solids (35 percent or less) for both systems occur
with low levels of solids recirculated, average oxidation, low fly ash
content, and high levels of carbonate.
High levels of settled bulk density, for lime and limestone product
sludges, of 1.4 g/cc or more are characterized by high oxidation, high
levels of solids recirculated, high fly ash content, and low sulfite solids.
As a contrast, low fly ash content, high percentages of sulfite carbonate,
and solids recirculated, plus low oxidation are noted for settled bulk
densities of 1.2 g/cc or less.
It should be noted that the main objective of the Shawnee Test
Facility is to evaluate various scrubber concepts and that the sludge
characterization study was a side effect to this scrubber evaluation.
As a result of this, no specific tests were conducted on the scrubber
to control the characteristics of the sludge produced. Since the sludge
characterization study has shown specific correlations between scrub-
ber operation and sludge characteristics the next step should be to
verify and demonstrate these correlations through actual control of
scrubber operation. Thus, a study should be made where the operation
of the scrubber is dedicated to sludge production and characterization
evaluations. This type of study could best be accomplished at a scale
smaller than Shawnee for economical purposes.
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Section 3
INSTRUMENTAL TECHNIQUES OF CHARACTERIZATION
During the period March 13, 1975, to June 30, 1977, slurry and solids
characterization studies have been conducted on 167 samples obtained from
the TCA and Venturi/spray tower scrubbing systems located at the Shawnee
Test Facility. A number of instrumental techniques have been employed in
this characterization. Scanning electron microscopy (using a Cambridge
S-A SEM) and optical microscopy provided both qualitative and quantitative
information concerning bulk solids composition, as well as the specific
morphological form in which various individual components occur. Infra-
red spectrophotometry (using a Perkin-Elmer 521 grating instrument) and
x-ray powder diffraction measurements (using Phillips-Norelco x-ray
generators and goniometers) have been used for semiquantitative analyses
of the dried solids and to determine crystallographic unit-cell parameters
of CaS03*0.5H20. The specific surface area of the dried solids was deter-
mined as an indication of solids component morphology. Since a portion
of this study involves investigation of the degree to which the calcium
sulfate hemihydrate component may have been substituted by sulfate or car-
bonate species, several techniques have been used which would reflect any
changes in crystal structure caused by this substitution. Optical micros-
copy was used to provide the index of refraction of this component, while
its specific crystallographic unit-cell parameters, as determined by x-ray
diffraction, are very sensitive to compositional changes. In addition,
differential scanning calorimetry (DSC) using a Perkin-Elmer DSC-2 was
evaluated as an indicator of the ease with which the sulfite component
underwent dehydration. It was felt that the temperature of dehydration
should, in general, vary inversely with the degree of substitution of
sulfate for sulfite.
Slurries obtained from the scrubbing systems were characterized by
static settling tests. Values for the settled bulk densities and settled
percent solids also were determined.
The results of the chemical and physical examination of the slurries
and solids are presented in Tables 1 and 2. A discussion of specific
areas of investigation follows.
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Section 4
SOLIDS MORPHOLOGY
Solids samples obtained from the TCA and venturi/spray tower, when
operated under nonoxidizing conditions, generally contain calcium sulfite
hemihydrate and fly ash as the major species. Small quantities of gypsum,
unreacted absorbent, and quartz are also present.
Sulfite Morphology
The calcium sulfite hemihydrate species is generally the major com-
ponent (50 to 70 percent by weight) of the solids. A study of its morpho-
logy and occurrence is important since these factors bear heavily on
handling considerations such as sludge filtration, clarification, and
disposal technique. It should be noted throughout this report that the
crystalline species referred to as calcium sulfite hemihydrate may be more
appropriately described as Ca(S03) (S04) 'zH20 or (CaS03) (CaS04) "zR2Q
where x is much greater (in the range of^10 times greater* than y and z
approaches 0.5.
The specific physical form in which the sulfite species appears is
directly related to the type of absorbent used (lime or limestone) and
is independent of the scrubber configuration (TCA or venturi/spray tower).
The calcium sulfite hemihydrate component of the solids samples received
during this study occurs in several forms (see Figure 1 for examples).
When limestone is used as the absorbent, the sulfite crystallizes pre-
dominantly as well-formed single plates with a length-width-thickness
average ratio of 25:20:1 (Figures 1A and IB). While within a given sample,
the crystal size distribution will range over an order of magnitude, the
average size may differ only by a factor of two to three from one sample
to another within the same run. The sulfite crystals in Figures 1A and IB
show the general maximum and minimum sizes observed in limestone runs dur-
ing this study. While the single plates described above are the major
form observed, aggregated forms of the sulfite crystals also are seen. An
example of a form appropriately described as a flat or two-dimensional
"rosette" in which many small plates grow outward in all directions,
particularly at low angles, around an axis perpendicular to the plane of
growth is shown in Figure ID. This form is not uncommon; most samples
examined from limestone-scrubbing operations will contain some incidence
of this rosette form. A few samples have shown this form as the predomi-
nant sulfite occurrence. A more open form of aggregate resulting from the
use of limestone is shown in Figure 1C. These forms consist of interpene-
trating plates forming relatively open structures of varying size and
shape; their occurrence in small amounts is a common feature.
The characteristic form of the sulfite precipitated from scrubbing
liquors where lime is used as the absorbent is shown in Figures IE and IF.
These generally spherical aggregates do not show a wide variation (usually
less than an order of magnitude) in size distribution within a given sam-
ple, although incompletely developed forms and fragments are often seen.
Examination of these spherical aggregates with transmission electron
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microscopy was undertaken to determine whether or not the aggregates pos-
sessed a central core of nonsulfite material (i.e., fly ash) which may
have served as an initial nucleation site. Results obtained with this
method were inconclusive due to particle decomposition and fragmentation
by beam heating effects. It may be noted, however, that spherical aggre-
gate formation is commonly seen in lime scrubbing operation under fly ash-
free conditions. Therefore, to clearly demonstrate that the sulfite habit
is scrubber-independent and absorbent-dependent, the samples obtained from
the venturi/spray tower scrubber over the period March 13, 1975, to June 27,
1976, may be subdivided into five separate groups:
A. 3-13-75 to 10-5-75, lime scrubbing, Figure 2
B. 10-12-75 to 1-31-76, limestone scrubbing, Figure 3
C. 2-15-76 to 3-2-76, lime scrubbing, Figure 4
D. 3-6-76 to 4-21-76, limestone scrubbing, Figure 5
E. 5-1-76 to 6-27-76, lime scrubbing, Figure 6
During this period the use of limestone as the absorbent was alternated
with that of lime as seen above. The results repeatedly show the spheri-
cal sulfite aggregate occurrence (Figures 2, 4, and 6) when lime is used.
When limestone is used, however, flat plates are seen to predominate
(Figures 3 and 5). A probable cause for this clearly-established absorbent-
morphology relationship appears to lie in the difference in precipitation
rates for the two forms; i.e., the spherical aggregates formed under lime
scrubbing operation are a result of much faster sulfite precipitation than
the larger single plates formed with limestone operation. Several factors
argue in favor of this explanation. One of the most significant features
is the obviously greater complexity of the sulfite forms precipitated when
lime is used. Complex crystalling forms; rather than larger single crystals,
are commonly observed when precipitation rates are high. Also, the optical
and x-ray crystallographic properties (index of refraction, lengths of
unit-cell axes) show greater variation in the lime-derived sulfite. These
properties are very sensitive to variations in the crystal structure of
the compound caused either by inclusion of ions "alien" to the parent
lattice (Na , K , S04~, S03~, etc.) or by large scale lattice defects of
a nonstoichiometric nature. Both foreign ion inclusions and lattice
defects are commonly a result of rapid precipitation. Another contribu-
ting piece of evidence is the difference in particle size distributions
observed between limestone- and lime-derived sulfite forms. The much
wider distribution of crystal sizes seen in samples consisting of single
plates indicates continual crystal growth. The narrower distribution of
sizes seen among the spherical aggregates infers a more rapid initial
growth within this same sampling interval with growth having been termi-
nated at the maximum size permissible in the scrubbing system.
Special attention may be given to Figure 6F in which the aggregates
are seen to consist of much smaller, more densely inter-penetrating plates
than observed in other samples in this study. Although the exact cause
of this differentiation is unknown, it should be noted that the level of
the chloride ion in the scrubbing liquor is much higher for the time at
which this sample was taken (2.13 percent by weight) than for any other
sample studied in this system.
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In lime systems, no definite relationship was seen between aggregate
size or complexity and either chemical composition or physical/chemical
operating conditions. In attempts to determine such a relationship,
factors such as stoichiometric ratio, pH, slurry temperaturea hold tank
residence time, make/pass, L/G, weight percent of Mg or Cl in the
liquor, and the presence or absence of fly ash were studied.
When limestone is used as the absorbent, the average size of the
plate crystals formed in this environment appears to be inversely related
to system stoichiometry, as shown in Figures 7A through 7F. The micro-
graphs show a steadily decreasing average crystallite size with increasing
Ca:S ratio. While no precise mathematical relationship has been derived,
this observation argues in favor of stoichiometries approaching 1,0 in
order to promote faster slurry filtration and clarification. Unfortunately,
S02 removal efficiency suffers at such low stoichiometries.
Attempts also have been made to relate crystal morphology (in lime-
stone operation) to factors such as pH, percent solid oxidation, slurry
temperature, hold tank residence time, make/pass, L/G, and percent Cl or
Mg in the liquor. No definite correlations have been seen. This fail-
ure to observe such relationships, here and in the lime systems discussed
above, is viewed to be a result of inadequate or insufficient data rather
than a lack of such relationships.
During the course of examination of samples received, a form of
"mixed crystal" was observed occurring during the period January 1, 1976,
to January 10, 1976, in both the TCA and venturi/spray tower systems and
is shown in Figures 8 and 9. The usual appearance of the mixed crystal
is that shown in Figures 8A, 8C, 9A, and 9B where a sulfite rosette appears
in intimate physical association with a well-developed, although often
imperfect, gypsum crystal. The gypsum crystals often show a large number
of surface cracks and longitudinal crystal defects. Enlarged views of the
areas of contact between the two forms show what appear to be CaSOg'O.SHgO
plate crystals growing from the body of the gypsum prism. Figure 8B is
such an enlargement of a contact zone of the form shown in 8A; note also
arrows in Figures 8D, 9C, and 9D. Occurrence of these "mixed crystals"
rarely has been observed in samples other than those included in the time
period quoted above and in these samples only in minor (less than 5 per-
cent) quantities. These forms may be related to the gypsum-calcium sulfite
hemihydrate solid solutions discussed by Borgwardt.1 Comparison of sample
chemical composition and scrubber operating data for the period of time
during which these samples were taken indicates no excursions from normal
values which might be helpful in explaining the sudden appearance of these
mixed forms. A possible explanation for the occurrence of the "mixed"
forms is that the severe chemical, pH, and thermal gradients present in a
scrubbing system provide an excellent environment for the precipitation of
disordered, nonequilibrium crystals. Particularly under conditions of
rapid precipitation and growth, crystals are easily formed having incor-
porated within their lattice ions which "do^not belong11 due to either
stoichiometric or radius ratio effects (S03~ inclusions in a CaS04*2H20
lattice, for example). As a result of internal electrostatic forces,
these "foreign" ions will tend to migrate through the parent crystal
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these "foreign" ions will tend to migrate through the parent crystal
lattice and, through a process of electrostatic segregation, form locally
stable domains. When these domains are on the surface of a crystal,
changes in the liquor chemistry and temperature surrounding the parent
crystal can cause this originally small domain to grow outward in the form
of another, but related, chemical compound through natural processes of
precipitation and, where useful, dissolution of the parent crystal.
The occurrence of this process of exsolution and subsequent crystal
growth on nucleation sites provided by surface domains is strongly sug-
gested by the contact surfaces shown in Figures 8B, 9C, and 9D.
Morphology of Accessory Components
Under the general heading "accessory components" are included those
materials which either are not directly involved in the desulfurization
reaction or are present in such small quantities that their presence does
not affect bulk sludge properties.
Fly ash is the most important of the accessory components in sludge
samples obtained in this study from normal operations, compromising 20 to
40 percent by weight of the solids composition. It is normally present
in the form of featureless spheres ranging in diameter from submicron
sizes up to those greater than 150 microns. The spheres may be solid or
hollow and consist of an amorphous aluminosilicate material usually con-
taining calcium and/or iron. A portion of the fly ash is magnetic and
ranges in quantity from 5 to 60 percent by weight. The presence of fly
ash should exert some influence on liquor chemistry; samples of fly ash
studied by other laboratories have shown neutralizing values of up to 4
meq/g.7'8 A small fraction of the fly ash constituent is not spherical
but appears as irregularly shaped vesicular particles. Occasionally
CaS03'0.5H20 plate crystals will be observed to have been precipitated
on the surface of fly ash spheres.
Gypsum (in unoxidized systems) and unreacted absorbent are generally
observed in very small quantities (less than 5 percent total by weight).
The CaS04-2H20 occurs primarily as broken and partially decomposed
prisms (left center, Figure 3C) or as twinned forms (Figure 5B). Unreacted
absorbent will be seen as partially or almost completely dissolved irregu-
lar forms (right center, Figure 5A and bottom center, Figure 7B). Unburned
coal and quartz are sometimes present in small amounts.
Morphology of Solids Formed Under Forced Oxidation
During the first quarter, 1977, forced oxidation tests were conducted
by installation of an air sparger and accessory reaction tanks in the
venturi scrubbing train. The results of this modification may be seen in
Figure 10 in which micrographs of solids from analysis points 1816 (spray
tower hold tank, no oxidation) and 1815 (venturi reaction tank, oxidation)
are shown for comparison. Where forced oxidation has been used (Figures
8B, 8D, and 8F), the primary reaction product appears as large, blocky
-------
gypsum crystals as compared to the much smaller single plates and open-
form aggregates (Figures 8A, 8C, and 8E) typical of routine limestone
operation. The CaS04*2H20 crystals formed in this mode of oxidation
are often broken and twined, and range in size from 10 to greater than
100 microns. Accompanying forms of CaSOs'O.SI^O are not observed.
Accessory components of sludge produced in forced oxidation tests are
equivalent to those found under routine operation.
-------
Section 5
SLURRY SETTLING BEHAVIOR
The settling behavior of slurries received during this study has been
determined by a static method. The samples, approximately I liter in
volume, are transferred to 1-liter graduated cylinders (inside diameter of
6 cm and with a depth of 42 cm), mixed thoroughly by stirring and repeated
inversion of the cylinders, and then allowed to settle. The height of the
solids-liquid interface is tabulated and plotted as a function of time.
The settled bulk density is calculated from Equation 1.
n - (B-A) - D(C-E)
Psb ~ E
where:
p , = settled bulk density, g/mL
A = weight of empty cylinder, g
B = weight of cylinder + slurry, g
C = initial volume of slurry, cm3
D = density of resulting supernatant fluid (after settling), g/cm3
E = volume of settled slurry, cm3
The density measurement, D, was initially determined by liquid pycnometer
measurements of aliquots taken from various levels within the supernatant
liquor. The results indicated that no detectable density gradient existed
within the liquid; therefore, all subsequent density measurements were
made with a hydrometer calibrated over the range 1.000 to 1.2000 g-cm"3.
The settled percent solids are calculated from Equation 2.
settled solids, % =
(% solids in initial slurry) x (total wt. of slurry sample)
(weight of settled slurry)
The weight of the settled slurry, including entrapped liquor, is obtained
by subtracting the weight of the supernatant liquor (obtained by density
and volume measurements) from the total weight of the slurry sample.
Sludge settling rates are known to be a function of temperature,
increasing temperature causing an increase in settling rate. However,
because of temperature gradients existing within the scrubber process
train and seasonal variations in clarifier temperatures, all settling
tests in this study were performed at room temperature.
The sedimentation behavior of particulate (nonflocculant) slurries
may be described generally by three basic modes: clarification, zone
settling, and compression; with clarification applying at low solids con-
centration and compression applying at very high percent solids. In the
clarification mode, individual particles settle independently at constant
rates which are primarily dependent on particle size and shape (Stokes1
10
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Law applies). Considerable particle size classification occurs with the
larger particles settling first and the smallest settling last. In the
zone settling mode, the particles are conceived to be all locked into a
plastic structure with very little independent settling (results from
higher percent solids). Here, the solids subside as a consolidated
structure so that ideally a single settling rate may be ascribed to all
particles; this settling rate will be a function of solids concentration
although individual particle morphology may play a part because of its
effect in determining the degree of porosity of the consolidated structure.
Ultimately, with very high solids concentration or towards the end of any
static settling test, the regime of compression settling will be reached.
In this mode, the hydrostatic bearing capacity of the settled solids,
including entrapped liquor, is assumed to be approximately equal to the
load produced by the settled solids plus any overlaying liquid. Under
these conditions, subsequent subsidence will occur primarily through the
formation of dewatering channels or the rake action at the bottom of a
clarifier.
Under average conditions in this study (limiting cylinder diameter,
static settling, 12 to 25 percent solids in slurry), zone settling most
often applied in that there was very little particle size or shape classi-
fication during settling; i.e., the entire body of solids settles simul-
taneously by dewatering. There was very little free particle settling.
Rather, all particles settle together, their combined weight gradually
forcing the water contained within the slurry past them to the top of the
interface. As the settling slurry approaches the compression stage,
"dewatering channels" were seen in cross section through the glass cylin-
der walls. These channels gave the appearance of dendritic or tree-like
structures arising from many small channels at a depth of 7 to 8 cm.
beneath the interface and graually coalescing into a single channel which
allowed the water to escape from the settling solids.
As slurry solids content decreases below 10 percent, clarification-
type settling is seen and individual particles settle according to their
own size and weight. The average settling rate is very rapid (2 to 10
times faster than with slurries containing 15 to 25 percent solids), and
the solids-liquid interface is quite indistinct, often definable only
after compression settling is approached.
Settling rates for solids of similar particulate morphology are
generally dependent on solids concentration. Slurries with high solids
concentrations settle more slowly. This may be illustrated with reference
to Figure 11A in which the settling rates for some limestone slurries are
shown by a plot of interface position as a function of time. Individual
curves are labelled for sample identification and original slurry percent
solids. Thicker (higher solids concentration) slurries have lower settling
rates and take longer to reach the compression stage. Slurry settling rate
behavior is complicated by the fact that the solids component morphology
can exert a strong influence. As an example of this effect, behavior of
slurries obtained from the TCA system on May 14, 1976, and April 12, 1976,
(Figure 11B) may be compared. Although the solids content by weight in
both slurries are essentially the same, the April sample settles more than
three times as fast and attains, when settled to compaction, an ultimate
solids content of 68 percent compared to 38 percent for the May sample.
11
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Inspection of the micrographs of these solids (Figure 12) reveals that
while both contain a predominance of single plates, the May sample consists
primarily of very small plates and plate fragments. These smaller parti-
cles inhibit settling and entrap more liquor upon reaching the compression
stage due to a higher degree of inter-particle contact and sample surface
area. This in turn limits the amoung of liquor that may flow past parti-
cles during settling and increases the difficulty with which dewatering
can occur upon reaching the compression stage.
The general relationship between sludge settling rate and percent
solids for all samples included in this study is shown in Figure 13.
To illustrate the differences in settling rates caused by solids morpho-
logy, lime slurries (spherical aggregates) are indicated by the character
"o," limestone slurries (plates) by a "D," and slurries obtained during
forced oxidation tests (blocky gypsum crystals) by an "x." In the range
10 to 25 percent solids, both lime- and limestone-derived slurries show
essentially the same linear, inverse relationship to settling rate. On
entering the regime of clarification settling, however, the behavior of
the two types of slurries differs. The hydrodynamically preferable
spherical forms precipitated with lime scrubbing demonstrate more rapid
size classification and less hydrodynamic drag during settling than do
the plates or open aggregates of limestone operation and, therefore, show
a more rapid increase in settling rate within the same range of solids
content. The gypsum slurries produced under conditions of forced oxidation
settle at the noticeably faster (5 to 10 times) rate than the other slur-
ries even though the slurry solids content enforces zone settling. The
crystals' very large size forms a settling structure which is relatively
open to water and thus allows less hindered settling although independent
settling of particles will not be allowed. The greater degree to which
these slurries may be dewatered is reflected in the observation that the
slurry produced with no oxidation settles to a final solids content of
23 percent with a bulk density of 1.17, while the gypsum slurry settles
in a much shorter time to a final 61 percent solids and bulk density of
1.55.
Figure 14 shows the relationship between the bulk density of the
settled slurries and their settled solids content. An approximately
linear, positive relationship is seen between these two properties. Lime
and limestone slurries show essentially the same behavior.
Fly ash-free test runs on both the TCA and venturi/spray tower systems
during this study provided data on slurry properties which may be com-
pared with that derived from normal operations. Based on these data, the
absence of fly ash has not clearly shown any effect on sludge property
relationships as shown in Figures 13 and 14. In Figure 15 are shown the
frequency distributions for the values obtained for the settled solids
content of lime and limestone slurries and for all slurries taken from
fly ash-free (<10 percent ash) runs. While both lime- and limestone-
derived slurries exhibit essentially the same behavior, the slurries con-
taining no fly ash seem to settle to a slightly lower final solids content.
Due to sample handling and shipping, the static settling tests per-
formed at Muscle Shoals were conducted from 3 to 14 days after the samples
were taken from the process loop. Settling tests conducted at the Shawnee
12
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Test Facility, however, are generally performed within a short time after
acquisition. In addition, settling data at Shawnee are generated by the
Dorr-Oliver method which differs from a static test in that the bottom of
the test cylinder contains a rake rotated at 1/6 rpm during the test. In
order to compare data generated by the two methods and to evaluate possi-
ble effects caused by the delay in testing, a program of comparison tests
was conducted. The results of this work are contained_in Table 3. The
mean value of the difference in the two measurements, y, is 3.6 with a
standard deviation of 10.8; the standard error of y is 10.8/^26 or 2.12.
The t-distribution value for 25 degrees of freedom and 95 percent double-
sized confidence limit is 2.06, so the limits are 3.6 ± 2.06 x 2.12 or
7.96 to -0.76. Based on this information, no bias is conclusively shown
between the two procedures.
13
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Section 6
SOLIDS SURFACE AREA MEASUREMENTS
The size, shape, and complexity of individual solid particles in the
scrubbing slurry are important in that these factors may influence or con-
trol processes such as chemical reaction, filtration, or dewatering rates.
An indirect indication of the average particle size and complexity of the
slurry solids is available in measurements of the solids surface area.
The equipment and methodology necessary to perform this measurement have
been developed and implemented for routine characterization of dried
scrubber solids. The specific instrumental technique used is a nitrogen
desorption method based on a variation of the single point B.E.T. method
and is adequately described in the literature.2
Previously dried samples are placed in glass U-tubes approximately
10 cm in length and swept for 1 hour with a purge gas (30 percent nitrogen
in helium) at a rate of 80 ml-min l, after which analysis is performed on
the sample without removing it from the tube. Values for the surface area
(M2/g) of samples received during this period are reported in Tables 1 and
2. This method yields a precision of better than 1 percent and an accuracy
of better than 5 percent.
Figure 16 shows the frequency distribution of surface area values.
The solid lines show the results of all measurements, while the dashed
lines indicate measurements made under "fly ash-free" (ash <10 percent)
conditions. Note that the average specific area for samples obtained dur-
ing lime scrubbing is greater than that measured for samples taken from
systems employing limestone. This difference in surface area values
reflects the differences in average particle size and morphology in lime
and limestone slurries and correlates with the observation that lime slur-
ries are more difficult to dewater than limestone slurries.
The frequency distribution of surface area values for fly ash-free
runs shows essentially the same form as displayed by all runs combined.
This indicates that the surface area component contributed by the fly ash
is not a critical factor in determining sludge characteristics.
14
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Section 7
THERMAL ANALYSIS OF SCRUBBER SOLIDS
Thermal analysis of selected dried scrubbing solids was employed
using differential scanning calorimetry (DSC) in the range 330° to 500°C.
This temperature range was selected in order to study the thermal dehydra-
tion of the CaS03*0.5H20 component. It was felt that substitution of car-
bonate or sulfate into the sulfite structure would result either in a shift
of this compound's desolvation temperature away from the observed in the
pure state or in an increase in complexity of the normally straightforward
endothermic desolvation reaction. All samples studied were analyzed using
a Perkin-Elmer DSC-2 differential scanning calorimeter. The temperature
scan rate used was 10°C/min, and dry nitrogen at a rate of 20 mL/min was
used as the purge gas. Prior thermal conditioning consisted of preheating
the samples (in the instrument) at a temperature of 330°C for a period of
15 min. All samples were analyzed in nonvolatile sample pans (small
aluminum containers of approximately 0.25-in. diameter and 0.125-in. depth,
with aluminum cover discs lightly crimped in place to prevent sample loss
but not hermetically sealed).
Two types of thermal activity were observed. The type of behavior
illustrated in Figure 17A has been observed to predominate in samples
taken from lime-scrubber systems. Here a generally straight-forward endo-
thermic desolvation of the sulfite occurs only after an initial reaction
which may represent a gradual desolvation or decomposition of an unknown
compound.
Figure 17B shows a type of thermal activity which is representative
of limestone systems. In this case no initial thermal activity is seen,
but the endothermic reaction attributed to the sulfite decomposition
clearly consists of at least two components, although inadequately resolved.
The dashed curve superimposed on Figure 17B shows the thermogram produced
by the thermal decomposition of pure CaS03'0.5^0 prepared in our
laboratory.
Thermal analysis of lime/limestones scrubbing materials has been
reported previously.3 In these studies, synthetic scrubbing solids were
prepared by the addition of fly ash to mixtures of the pure components
normally found in such sludges (CaS03*0.5H20, CaS04'2H20, CaC03, etc.)
These mixtures were studies by differential thermal analysis (DTA) and
thermogravimetric analysis (TGA). The CaSOa'O.S^O was found to undergo
dehydration in the region 350° to 410°C. This compares favorably with
our results which indicate an average decomposition temperature of approxi-
mately 390°C. These values represent a deviation from the dehydration
temperature of 367°C for the pure compound as reported by Schropfer4
utilizing DTA. DSC investigation of the pure compound prepared in TVA's
laboratory indicates a decomposition temperature of 364°C.
It is not clear which aspects of the complex thermal behavior of the
samples examined to date are a result of matrix effects and which may be
assigned to reactions of carbonate- or sulfate-substituted CaSOs'
species. An attempt was made to clarify this situation by using
15
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H20-saturated N2 as the purge gas. Ideally an increase in the partial
pressure of H20 in the gas environment surrounding the sample should have
displaced the dehydration temperature of CaS03'0.5H20. This effect was
not observed due to instrument noise caused by microdroplets of water in
the gas stream.
The primary purpose of this study was to show any relationship
between the dehydration temperature of CaS03*0.5H20 and other indicators
of structure perturbation (optical index of refraction, length of crystal-
lographic unit cell axes as determined by x-ray diffraction, etc.). Ther-
mal analysis of 57 samples did not show any definite relationship between
the desolvation temperature of the hemihydrate and any other indicator of
crystal structure perturbation. The reason for apparent failure to show
any defined relationship is attributed to lack of adequate precision in
both thermal and crystallographic data, although the former is likely to
play the major role. Data obtained from these experiments are shown in
Table 4.
As an offshoot of this work, a simple and rapid method for determina-
tion of CaS04'2H20 in scrubber solids was developed. It was shown that
the peak area resulting from gypsum dehydration is directly and linearly
proportional to the percent of gypsum in the sample5'6 (in DSC, peak area
is proportional to the AH of reaction). This peak is not obscured or
interfered with by other components in the sample matrices studied and
thus provides a clear-cut distinction between gypsum S04~ and substituted
804 within the sample. Over the range 10 to 0.3 percent gypsum, determi-
nations may be made with a precision of better than 5 percent and an
accuracy of better than 5 percent.
Calibration standards over the range 0.06 to 10 percent were prepared
by adding pure gypsum to a matrix prepared by batch heating a selected
dried scrubbing sludge (original composition: 35 percent ash, 12 percent
CaC03, 42 percent CaSOs'O.SI^O, and 10 percent gypsum) at a temperature
of 200°C for 24 hours. Examination of this reference matrix by infrared,
x-ray diffraction, DSC, arid optical microscopy after heating revealed no
trace of residual gypsum. Samples of scrubber solids to be analyzed were
dried at a temperature of 50°C (in the instrument) to a constant baseline
to remove surface-adsorbed H£0. The previously prepared inert (over the
temperature range of interest) matrix was used as a reference material.
A temperature scan rate of 10°C/min was used for both samples and unknowns.
Samples of known materials were prepared by adding known, weighed amounts
of CaS04'2H20 to dried sludge samples which had been found by x-ray, IR,
and DSC to contain no gypsum. These samples were analyzed and compared to
the previously prepared calibration curve. Results of this investigation
are in Table 5. While this procedure is fairly accurate over the range 10
to 0.5 percent (weight) gypsum, inaccuracy due to difficulties in preparing
solid mixtures at these levels increases quickly below 0.5 percent. The
method is easily extended to gypsum contents higher than 10 percent,
although an inert diluent may be necessary above 20 percent gypsum.
16
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Section 8
STATISTICAL ANALYSIS
The statistical analysis of sludge data from the venturi/spray tower
and TCA systems centered on determining typical operating conditions for
the duration of the data and an examination of extreme results (both high
and low) of settled bulk density, percent settled solids, and their asso-
ciated variables. These variables were then examined for possible causi-
tive effects on settled bulk density and percent settled solids. Estimates
of variation with regard to both typical and extreme operating conditions
were made so significant changes in the response of settled bulk density
and percent settled solids could be identified. Nonlinear regression
models were developed which characterized the behavior of settled bulk
density and the percentage of settled solids. Summary tables (6 to 10)
are presented for average and extreme values for all variables.
In the presentation of these analyses, the total calcium content of
the sludge (that which is bonded to sulfite, sulfate, and carbonate) is
reported as CaO. Also SQ%, SOa, and C02 represent the relative quantities
of sulfite, sulfate, and carbonate in the sludge.
Mean Values
Mean values and standard deviations are presented in Table 6 for both
the lime and limestone product sludges studied over the test period. Iden-
tification of high and low ranges of the variables are also presented.
For the lime product sludges, the following averages were seen: oxidation,
20 percent; settled solids, A3 percent by weight; settled bulk density,
1.3 g/cc; and 10 percent solids recirculated. The solids, by weight, had
an average composition of 32 percent fly ash, 29 percent CaO, 25 percent
sulfite, 7 percent sulfate, and 1.5 percent carbonate. Averages of the
limestone product sludge data show 22 percent oxidation, 41 percent set-
tled solids, 1.3 g/cc settled bulk density, and 15 percent solids recir-
culated. The average solids analysis is 33 percent fly ash, 30 percent
CaO, 21 percent sulfite, 6 percent sulfate, and 5.5 percent carbonate.
Percent Settled Solids
The following mean values were associated with high levels (57.9 per-
cent) of settled solids for the lime product sludges: high natural oxida-
tion, 38.6 percent; high percentage of solids recirculated, 14.5 percent;
high fly ash content, 39.5 percent; and low levels of calcium sulfite
solids, 18.6 percent. Two samples under a program for forced oxidation
had oxidation in excess of 95 percent. This was with an average of 18.6
percent solids recirculated, 55.7 percent fly ash, 0.5 percent sulfite
solids, and 65 percent settled solids.
The limestone product sludges also had two groups of data with high
levels of settled solids. One group had an average oxidation of 17.9
percent. This group was characterized by 17.7 percent solids recirculated,
17
-------
a fly ash content of 38.6 percent, and settled solids of 53.2 percent.
The second group obtained during forced oxidation testing had an average
oxidation of 98.3 percent with settled solids of 63.3 percent, fly ash
content of 64.5 percent, and extremely low sulfite solids of 0.2 percent.
Table 7 summarizes the data characteristic of high settled solids.
Low levels of settled solids were also examined for the lime and
limestone product sludges to obtain further information on the behavior
and effects of variables associated with the percent of settled solids.
The lime product sludges had an average of 26.9 percent settled solids
with mean oxidation of 14.8 percent, 8.8 percent solids recirculated, fly
ash content of 17.0 percent, and a high level of sulfite solids of 25.2
percent. Also at high levels were CaO at 37.5 percent and carbonate at
2.8 percent.
The limestone product sludges exhibited similar behavior at low
levels of settled solids. An average of 26.9 percent settled solids was
associated with 15.6 percent oxidation, 9.2 percent solids recirculated,
and a fly ash content of 14.0 percent. The solids were composed of 27.2
percent sulfite, 38.8 percent CaO, and 7.2 percent carbonate. Table 8
summarizes the low settled solids characteristics.
Settled Bulk Density
Analysis of factors associated with settled bulk density indicated
the effect of high oxidation versus low oxidation levels. In general,
for the lime product sludges, a settled bulk density of 1.4 g/cc or more
was regarded as a "high" level.
The following were average values associated with low levels of oxi-
dation (11.4 percent average): settled bulk density, 1.43 g/cc; percent
recirculated solids, 7.6 percent; fly ash, 34.3 percent; CaO, 28.8 percent;
sulfite, 25.2 percent; and carbonate, 3.2 percent. For the high oxidation
group with a mean oxidation of 96.6 percent, the associated values were:
fly ash, 55.7 percent; percent solids recirculated, 18.6 percent; sulfite,
0.5 percent; carbonate, 0.3 percent; and CaO, 15.6 percent. For this high
oxidation group, the settled bulk density was 1.65 g/cc.
Settled bulk density for the limestone product sludges behaved simi-
larly. An average settled bulk density of 1.43 g/cc was associated with
an oxidation level of 11.4 percent. Typical average values for the other
variables were: percent solids recirculated, 15.2 percent; fly ash, 32.4
percent; CaO, 30.5 percent; sulfite content, 24.1 percent; and carbonate
content, 4.8 percent. The settled bulk density for the high oxidation
group was 1.61 g/cc with an average oxidation value of 98.3 percent. The
other average values were: fly ash, 64.5 percent; CaO, 12 percent; sul-
fite, 0.2 percent; carbonate, 0.7 percent; and 16.4 percent solids recir-
culated. Table 9 summarizes the high settled bulk density data.
In general, the lower settled bulk density for both lime and limestone
systems was associated with low oxidation, low fly ash content, and a lower
than average percent solids recirculated. At the same time high levels
18
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of CaO, sulfite, and carbonate solids occurred. Table 10 illustrates
the low settled bulk density data.
Relationships Found in the Data Using Regression Analysis
The data were extensively examined for relationships between the per-
centage of settled solids and settled bulk density and those variables
which determine their behavior. The two variables having the largest
effect on both settled solids and settled bulk density are the percent
sulfite solids and percent solids recirculated. The analysis resulted in
equations which quantify the response of settled solids and settled bulk
density to changes in the percent sulfite solids and percent solids recir-
culated. It must be noted that these equations pertain only to the ranges
of data which occurred in this study. The Equations are:
Lime: % settled solids = 39.6 X/0'09 X2°'15 (3)
= i7.ixr°-09xs
0.09
Limestone: % settled solids =17.1 Xj'0'09 X2°'42 (5)
p . = 1.15 Xj X2
Ksb * £
where: p , = settled bulk density, g/mL
S D
Xj = wt. % sulfite solids
X2 = wt. % solids recirculated
As an example, Equation 5 for limestone product sludges predicts an
average of 40.9 percent settled solids for 21 percent sulfite solids and
15 percent solids recirculated.
% settled solids = 17.1(21.0)~°-09(15.0)0-42
In (% settled solids) = ln(17.1) - 0.09 1N(21.0) + 0.42 ln(15.0)
= 2.84 - 0.27 + 1.14 = 3.71
% settled solids = exp(3.71) = 40.9%
Table 6 indicates that this is a typical settled solids figure.
Table 11 summarizes the change in settled bulk density and percent
settled solids for changes in percent sulfite solids and percent solids
recirculated, using Equations 5 and 6.
For a constant percent solids recirculated, raising the sulfite con-
tent of the sludge decreases both settled solids and settled bulk density.
For a constant sulfite content, raising the percent solids recirculated
raises both the percent settled solids and settled bulk density. The last
two entries in Table 6 illustrate the response of settled solids and
settled bulk density to a combination of (1) low sulfite solids (0.4 per-
cent) and high solids recirculated (18.0 percent) and (2) a high sulfite
solids (37.0 percent) and low solids recirculated (5.0 percent). The low
19
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sulfite solids with high solids recirculated results in a predicted high
settled bulk density of 1.61 g/cc and high settled solids of 62.5 percent.
These predicted values correspond well to actual values of 1.65 g/cc and
62.8 percent which occurred at 0.4 percent sulfite solids and 17.8 percent
or 18.2 percent solids recirculated, respectively. The case of high sul-
fite solids and low solids recirculated indicates a low estimated settled
bulk density of 1.20 g/cc and low settled solids of 24.3 percent. Actually,
a 1.16 g/cc settled bulk density occurred at 36.3 percent sulfite solids
and 7.5 percent solids recirculated, while 24.9 percent settled solids was
noted at 36.6 percent sulfite solids and 7.6 percent solids recirculated.
The equations are seen to typify the behavior found in the data. Similar
calculations can be made for the lime system.
A more detailed explanation of the derivation of the equations and
the statistical analysis are presented in the next section.
Regression Models - Statistical Considerations
The behavior of the percentage of settled solids and settled bulk
density was further characterized by examining possible relationships with
associated variables. A nonlinear model best described the response of
settled solids and settled bulk density with the percentage of solids
recirculated and calcium sulfite content of the solids being the indepen-
dent variables. The model is:
BI 82
y = a Xi X2 e (7)
where Y is the dependent variable of percent settled solids or settled
bulk density, Xj is the percent of sulfite solids and X2 is the percent
of solids recirculated. The unknown parameters to be estimated are a,
B1} B2, with e being a random error. The model can be linearized by
taking natural logarithms which result in the following equation:
In Y = Inof + B! InXj. + B2 lnX2 + Ine (8)
which can be estimated by standard least squares analysis. For valid
tests of significance and confidence intervals, Ine must be N(0,Io2).
Table 11 presents the estimates Inot, bi, and b2 of Inot, Bj, and B2 with
the associated standard errors. Extensive examination of the residuals
did not indicate any model definciencies or violations of standard
assumptions necessary for least squares analysis.
The resulting models are given by Equations 3, 4, 5, and 6 which are
shown on page 19.
One indication of how well an equation fits the data is the multiple
correlation coefficient squared (R2). It estimates the proportion of
total variation explained by the regression. The F-value indicates how
significant, in a statistical sense, the coefficients are when taken all
together. Table 13 summarizes the R2 and F values from the regression
analysis plus the antilogarithm of the standard error of estimates.
20
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Figures 18 through 29 show the graphs of observed values versus pre-
dicted values from the nonlinear models. (For both limestone and lime and
the dependent variables of percent settled solids and settled bulk density).
Three types of graphs are plotted: (1) dependent variable versus percent
calcium sulfite solids, (2) dependent variable versus percent solids recir-
culated, and (3) observed dependent variable versus the predicted dependent
variable at the same values of the independent variables.
For example, Figures 18, 19, and 20 for limestone show how the per-
cent settled solids decline as a function of percent calcium sulfite
solids and increases as a function of percent solids recirculated, and
that the regression equation does fairly well in predicting the response
of percent settled solids. Examination of the other figures indicates
that the regression equations model the data well for the limestone
system, but not quite as well for the lime system.
21
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REFERENCES
1. Borgwardt, R. H., "Limestone Scrubbing of S02 at EPA Pilot Plant,"
EPA Progress Report, June 11, 1973.
2. Nelsen, F. M. and F. T. Eggertsen, An_alJ_Chem_1 30, 8 (1958).
3. Taylor, W. C. Combustion_45 (4), 1522 (1973).
4. Schropfer, V. L. , Zeitschr_ift__fiir_ Ajior^a£i^h£_urui_AJJ^enuMne Chemie
" - . -
____ __^
4CM (1), 114 (1973). " - . -
5. Schlichenmaier, V., Thermochemica Acta 11, 334-338 (1975).
6. Kuntze, R. A., Materi al s JRes_. _and__S_t d s^ , 640-642 (August 1962).
7. Martens, D. C., Com^qst__Science_ 12 (6), 15-19 (1971).
8. Martens, U. C., M. G. Schnappinger , and L. W. Zelazny, "The Plant
Availability of Potassium in Fly Ash," Soil Science Society of
America Proceedings, 34, 453-456 (1970).
FIGURE 1
Photomicrographs illustrating various forms in which CaS03'0.5H20 is
found in scrubber sludge.
A. Typical well-formed single sulfite plates formed when
limestone is used as the absorbent
B. Typical well-formed single sulfite plates formed when
limestone is used as the absorbent
C. Open form of aggregate sulfite crystal formed when limestone
is used as the absorbent
D. Aggregated form of sulfite crystal (rosette) formed when
limestone is used as the absorbent
E. Typical spherical aggregates of sulfite crystals formed when
lime is used as the absorbent
F. Typical spherical aggregates of sulfite crystals formed when
Lime is used as the absorbent
22
-------
Figure 1A
Figure 1B
Figure 1C
Figure 1D
Figure 1E
Figure IF
23
-------
FIGURE 2
Photomicrographs of CaSOs'O.Sh^O aggregates formed when lime is used as
the absorbent.
A. Spherical sulfite aggregates formed when using lime as the
absorbent on 4/11/75
B. Spherical sulfite aggregates formed when using lime as the
absorbent on 4/11/75
C. Spherical sulfite aggregates formed when using lime as the
absorbent on 9/28/75
D. Spherical sulfite aggregates formed when using lime as the
absorbent on 9/21/75
E. Spherical sulfite aggregates formed when using lime as the
absorbent on 10/5/75
F. Spherical sulfite aggregates fomred when using lime as the
absorben on 9/28/75
24
-------
rv *
Figure 2A
Figure 2B
Figure 2C
Figure 2D
Figure 2E
-------
FIGURE 3
Photomicrographs of CaS03'0.5H20 plates formed when limestone is used
as the absorbent.
A. Flat sulfite plates formed when using limestone as the
absorbent on 10/21/75
B. Flat sulfite plates formed when using limestone as the
absorbent on 10/12/75
C. Flat sulfite plates formed when using limestone as the
absorbent on 11/6/75
D. Flat sulfite plates formed when using limestone as the
absorbent on 10/28/75
E. Flat sulfite plates formed when using limestone as the
absorbent on 11/19/75
F. Flat sulfite plates formed when using limestone as the
absorbent on 11/19/75
26
-------
Figure 3A
Figure 3B
Figure 3C
Figure 3D
Figure 3E
Figure 3F
27
-------
FIGURE 4
Photomicrographs of CaS03'0.5H20 aggregates formed when lime is used as
the absorbent.
A. Spherical sulfite aggregates formed when using lime as
the absorbent on 2/15/76
B. Spherical sulfite aggregates formed when using lime as
the absorbent on 2/15/76
C. Spherical sulfite aggregates formed when using lime as
the absorbent on 2/21/76
D. Spherical sulfite aggregates formed when using lime as
the absorbent on 2/21/76
E. Spherical sulfite aggregates formed when using lime as
the absorbent on 3/2/76
F. Spherical sulfite aggregates formed when using lime as
the absorbent on 3/2/76
28
-------
Figure 4A
Figure 4B
Figure 4C
Figure 4D
Figure 4E
Figure 4F
29
-------
FIGURE 5
Photomicrographs of CaS03'0.5H20 plates formed when limestone is used
as the absorbent.
A. Flat sulfite plates formed when using limestone as the
absorbent on 3/28/76 (note: unreacted absorbent — right
center)
B. Flat sulfite plates formed when using limestone as the
absorbent on 3/14/76 (note: twinned form of gypsum
crystal — right center)
C. Flat sulfite plates formed when using limestone as the
absorbent on 4/3/76
D. Flat sulfite plates formed when using limestone as the
absorbent on 3/20/76
E. Flat sulfite plates formed when using limestone as the
absorbent on 4/21/76
F. Flat sulfite plates formed when using limestone as the
absorbent on 4/21/76
30
-------
Figure 5A
Figure 5B
Figure 5C
Figure 5D
Figure 5E
31
Figure 5F
-------
FIGURE 6
Photomicrographs of CaS03'0.5H20 aggregates formed when using lime
as the absorbent.
A. Spherical sulfite aggregates formed when using lime as
the absorbent on 5/15/76
B. Spherical sulfite aggregates formed when using lime as
the absorbent on 5/8/76
C. Spherical sulfite aggregates formed when using lime as
the absorbent on 6/9/76
D. Spherical sulfite aggregates formed when using lime as
the absorbent on 5/31/76
E. Spherical sulfite aggregates formed when using lime as
the absorbent on 6/27/76
F. Densely inter-penetrating (aggregates) sulfite plates
formed under elevated levels of chloride ion (2.13 wt
percent) when using lime as the absorbent on 6/20/76
32
-------
Figure 6A
Figure 6B
1816 5/31/76 8738
Figure 6D
Figure 6E
Figure 6F
13
-------
FIGURE 7
Photomicrographs illustrating the relationship between
plate size and scrubber system Ca:S stoichiometry with limestone as
the absorbent.
A. Flat sulfite plates formed when using a Ca:S stoichiometry
of 0.98
B. Flat sulfite plates formed when using a Ca:S stoichiometry
of 1.06
C. Flat sulfite plates formed when using a Ca:S stoichiometry
of 1.13
D. Flat sulfite plates formed when using a Ca:S stoichiometry
of 1.27
E. Flat sulfite plates formed when using a Ca:S stoichiometry
of 1.43
F. Flat sulfite plates formed when using a Ca:S stoichiometry
of 1.63
34
-------
Figure 7A
Stoic.=0.98
Figure 7C
Stoic.= 1.13
Figure 7B
Stoic.= 1.06
Figure 7D
Stoic.-1.27
Figure 7E
Stoic.=1.43
Figure 7F
Stoic.= 1.63
-------
FIGURE 8
Photomicrographs of "Mixed Crystal" forms.
A. Sulfite rosette in intimate physical association with a
well-developed gypsum crystal
B. Enlargement of a contact zone of the sulfite rosette and
gypsum crystal of the form shown in A
C. Sulfite rosette in intimate physical association with a
gypsum crystal
D. Contact zone of sulfite and gypsum mixed crystal (note:
arrow)
36
-------
,1
^F Sfc
Figure 8A
Figure 8B
Figure 8C
Figure 8D
-------
FIGURE 9
High-magnification photomicrographs of sulfite-gypsum "Mixed Crystal"
forms.
A. Sulfite rosette in intimate physical association with a
well-developed gypsum crystal
B. Sulfite rosette in intimate physical association with a
well-developed gypsum crystal
C. Contact zone of sulfite and gypsum mixed crystal (note:
arrow)
D. Contact zone of sulfite and gypsum mixed crystal (note:
arrow)
38
-------
Figure 9A
Figure 9B
Figure 9C
Figure 9D
-------
FIGURE 10
Photomicrographs of sludge solids components with and without forced
oxidation on the same system (venturi/spray tower).
A. Flat sulfite plates formed with no forced oxidation in the
spray tower
B. Gypsum crystals formed with forced oxidation in the venturi
C. Enlargement of the sulfite plates shown in A
D. Enlargement of the gypsum crystals shown in B
E. High-magnification of the sulfite plates shown in A
F. High-magnification of the gypsum crystals shown in B
-------
Figure 10A
Figure IOC
Figure 10B
Figure 10D
Figure 10E
Figure 10F
-------
36
100
400
500
200 300
Time, min.
Figure 11A. Similar particulate morphology but different slurry percent solids
T
100
200 300
Time, min.
400
500
Figure 11B. Different particulate morphology but similar slurry percent solids
Figure 11. Slurry settling rate curves
43
-------
FIGURE 12
Photomicrographs of solids producing settling behavior shown in Figure
11B.
A. Small sulfite plates and plate fragments in TCA scrubbing
slurry sample of 5/14/76
B. Large sulfite plates in TCA scrubbing slurry sample of
4/12/76
44
-------
Figure 12A
Figure 12B
45
-------
120r-
• Lime
D Limestone
X Oxidation
1004
80
60
• •
40
X X
X
x
20
• • •
0
00 D • •o
0 00 • • «0 •
• 0 0 »0 0
• • 0
1 1
0 0 •• 0 •
00 000 0« 00000 • D 0
o 000 ooo •onn oo o
oo o« o OKID o oo o o
I 1
10
15
20
25
30
Solids Content, % (wt)
Figure 13. Settling rate of lime and limestone scrubber slurries
-------
1.7
1.6
1.5
• Lime
D Limestone
X Oxidation
XX
X
X
1.4
1.3
1.2
ODD*
• o on M
a D »a •
• •a o* a* a«a ••
••CD* D*D • a • Q
MOMOOD* •
• ••a *o
D DODO oa« • a •
D D D 0 DO •
0 • •
a* an
a • o «o» a
a
D D DO
•0
D
0
a
1.1
10
20
50
30 40
Settled Solids Content, % (wt)
Figure 14. Settled bulk density for lime and limestone scrubber slurries
60
70
-------
40
T
• All limestone runs
0 All lime runs
D All flyash free runs
30
C/)
O
QJ
O
-------
40
1 1 1 1 1 1 1 1 1 1
0 All limestone runs
1 1
O All lime runs
• Flyash free limestone runs
[3 Flyash free lime runs
-
A 5 6 7 8
Surface Area Value (ra2/g)
10
11
12
Figure 16. Distribution of surface area values for solids produced under
lime, limestone, and fly ash-free operation
-------
CJ
0)
co
00
0)
•o
4-1
•rl
>
•rl
4J
•H
CO
-------
o
o
O
o
to
o
o
10
10
0) O
? •
^ o.
s^ *
O O
co o
CO
O
O
o
o
-------
o
o
NON-LINEAR MODELS
(ORIGINAL SCALE)
0 - Observed
* - Predicted
-------
o
o
NON-LINEAR MODELS
(ORIGINAL SCALE)
PREDICTED=OBSERVEO
2:3.00 3\ .0039.00 47.00 55.00
Observed Value of Settled Solids, % (wt)
63.00
71 .00
Figure 20. Predicted and observed final settled solids content for lime-
stone scrubber slurries
53
-------
o
CD
NON-LINEAR MODELS
(ORIGINAL SCALE)
0 - Observed
* - Predicted
©
s
I
-------
NON-LINEAR MODELS
(ORIGINAL SCALE)
0 - Observed
° * - Predicted
o
r-
-------
o
oo
o
CO
NON-LINEAR MODELS
(ORIGINAL SCALE)
PREDICTED=OBSERVED
1 .10
1.20 1.30 1.40 1.50 1.60
Observed Value of Settled Bulk Density g/cc
1.70
1.80
Figure 23. Predicted and observed settled bulk density for limestone
scrubber slurries
56
-------
o
o
NON-LINEAR MODELS
(ORIGINAL SCALE)
0 - Observed
* - Predicted
©
O
O 0 (D
-------
NON-LINEAR MODELS
(ORIGINAL SCALE)
0 - Observed
* - Predicted
© ©
x
©
© ©
©
©
© *
*«r *«
w M^^
©
©
*li »*•»"<..
©ffi
©
o
©
4.00 8.00 12.00 16-00 20-00 24.00 28-00
Solids Recirculated, % (wt)
Figure 25. Final settled solids content of lime scrubber slurries as a
function of recirculated solids content
58
-------
NON-LINEAR MODELS
(ORIGINAL SCALE)
o
o
PREDICTED=OBSERVEO
15.00
23.00
Figure 26.
31.00 39.00 47.00 55.00
Observed Value of Settled Solids, % (wt)
63.00
71.00
Predicted and observed final settled solids content for lime
scrubber slurries
-------
o
CO
o
CD
o
o
:sj
j-i
en
a)
P
3
Pd
NON-LINEAR MODELS
(ORIGINAL SCALE)
0 - Observed
* - Predicted
-------
o
CO
NON-LINEAR MODELS
(ORIGINAL SCALE)
(!) - Observed
* - Predicted
(53
*K,
CD ffl
(0 O
O
-------
NON-LINEAR MODELS
(ORIGINAL SCALE)
o
CD
o
r-
o
CJ
•H
CO
C
OJ
s -
13
0)
M
P-i
O
CM
PREDICTED=OBSERVED
1.20
Figure 29
1.30 1.40 1.50 1.60
Observed Value of Settled Bulk Density, g/cc
Predicted
slurries
1.70
1.80
°bSerVed S6tUed bulk density of lime scrubber
62
-------
TABLE 1. TCA SLURRY ANALYSES
U>
RUN NUMBER 539-2A
ANALYSIS POINT 2816
DATE 031375
TIME 1300
ADSORBENT LS
ON-SITE SOLIDS ANALYSES
ASH (MT ft) 28.81
CA (MT ft) 31.33
S02 (MT ft) 15.81
S03 (MT ft) 7.08
CO? (MT ft) 11.36
TVA SOLIDS CHARACTERIZATION
ASH (MT ft* ACID INSOLUBLE) 25.0
CACO3 (MT ft* BY IRI 32.0
CAS03 X .5 H20 (MT ft, IR) 36.0
CAS04 X 2H20 (MT ftt IR) 6.8
SURFACE AREA (SO M/GH) 3.8
TVA SLURRY CHARACTERIZATION
SLURRY SOL I OS ft 15.5
SETTLED ft SOLIDS 44.7
SETTLED BULK DENSITY (GM/CC) 1.22
SETTLING RATE (CM/HR) 5.0
TVA CRYST ALLOGRAPH 1C ANALYSES
SULFITE REFRACTIVE INDEX 1.590
SULFITE A AXIS 9.790
STD. ERROR 0.017
SULFITE B AXIS 10.678
STO. ERROR 0.010
SULFITE C AXIS 6.503
STD. ERROR 0.008
SCRUBBER OPERATIONAL PARAMETERS
ft SOLID OXIDATION 26.40
SAT. RATIO (RADIAN 50 C.) 0.0
STOIC. RATIO 1.67
SLURRY PH 6.00
SLURRY TEMPERATURE (C) 50.0
HAKE/PASS ( MOLES/ THOUS GAL) 0.0
LIQ/GAS (6AL/THOUS CFM) 0.0
MT ft CL IN LIQUOR 0.19
MT ft MG IN LIQUOR 0.03
HOLD TANK RES. TIME (WINS) 25.0
539-2A
2616
031475
1300
LS
27.43
31.36
16.11
6.05
11.25
33.0
28.0
39.0
0.0
4.4
13.5
35.6
1.24
4.7
1.590
9.798
0.016
10.661
0.009
6.492
0.008
0.0
0.0
1.56
6.00
52.0
0.0
0.0
0.16
0.03
25.0
54 1-2 A
2816
032675
1500
LS
23.47
34.96
15.91
8.11
12.06
29.0
33.0
29.0
8.7
3.5
13.9
34.3
1.25
3.4
1.591
9.760
0.028
10.640
0.014
6.491
0.012
28.90
1.08
1.76
5.85
52.0
0.0
0.0
0.15
0.03
15.0
546-2A
2816
061175
1500
LS
47.53
23.92
19.03
3.46
2.55
43.3
11.6
34.7
10.4
2.8
14.9
44.9
1.30
6.6
1.590
9.795
0.006
10.695
0.007
6.551
0.004
12.70
1.21
1.25
5.70
50.0
60.0
33.4
0.33
0.02
15.0
546-2A
2816
061275
0700
LS
38.72
25.84
22.05
4.42
3.78
43.3
13.3
32.1
11.3
2.6
15.9
38.8
1.26
4.8
1.590
9.790
0.010
10.694
0.012
6.518
0.010
13.80
1.10
1.15
5.65
52.0
86.5
34.1
0.26
0.03
15.0
546-2A
2616
061775
0700
LS
29.55
30.18
25.95
3.66
5.21
26.7
16.9
48.0
8.4
2.5
15.6
40.6
1.32
5.3
1.593
9.800
0.015
10.689
0.014
6.515
0.012
10.10
0.40
1.14
5.95
50.0
107.4
33.9
0.20
0.03
15.0
557-2A
2816
080875
1426
LS
39.55
27.05
14.80
5.61
8.50
42.0
14.6
32.5
10.9
2.4
15.5
46.7
1.32
7.3
1.591
9.791
0.009
10.730
0.010
6.517
0.008
23.27
0.97
1.60
5.95
54.0
83.5
40.9
0.18
0.03
15.0
559-2A
2616
091475
0700
LS
35.62
28.93
17.30
4.95
8.66
35.0
20.1
35.9
9.0
3.7
16.2
39.9
1.30
4.3
1.589
9.766
0.006
10.700
0.008
6.520
0.006
18.60
0.46
1.55
6.05
52.0
85.9
40.3
0.16
0.03
15.0
5S9-2A
2816
092175
0700
LS
38.08
27.89
15.01
5.84
8.65
30.0
18.1
42.2
9.7
2.8
16.1
39.6
1.28
4.7
1.591
9.767
0.003
10.697
0.005
6.517
0.004
23.70
0.43
1.62
5.40
53.0
92.8
40.0
0.19
0.04
15.0
560-2A
2816
092875
0700
LS
32.34
30.29
21.32
3.70
7.78
35.7
35.7
30.7
8.4
3.4
9.7
35.8
1.24
7.9
1.590
9.792
0.017
10.693
0.012
6.510
0.010
12.10
0.37
1.42
5.70
50.0
0.0
42.0
0.17
0.04
15.0
561-2A
2616
100575
0700
LS
31.98
28.73
22.42
5.02
6.13
29.0
16.1
46.2
8.7
2.5
15.1
40.9
1.26
5.8
1.589
9.797
0.006
10.697
0.006
6.514
0.005
15.10
0.35
1.24
5.95
50.0
89.8
40.0
0.0
0.0
15.0
S62-2A
2816
101275
0700
LS
28.39
30.42
20.16
7.43
7.26
26.0
18.6
45.6
7.7
2.7
15.3
39.6
1.29
5.0
1.590
9.794
0.006
10.697
0.006
6.514
0.005
22.60
0.49
1.33
5.85
54.0
79.2
40.5
0.22
0.03
12.0
562-2A
2816
102175
0700
LS
33.68
31.20
18.62
6.12
6.15
29.0
21.3
41.2
8.5
3.5
14.2
39.4
1.2S
4.6
1.589
9.768
0.007
10.702
0.-007
6.512
0.005
20.80
0.0
1.52
5. SO
50.0
84.6
40.3
0.0
0.0
12.0
LS = Limestone
-------
TABLE 1. TCA SLURRY ANALYSES
RUN NUMBER 562-2A 562-2A 563-2A 564-2A 565-2A 567-2A 568-2A 570-2A 571-2A 566-2B 575-2A 5T7-2A 579-2A
ANALYSIS POINT 2816
DATE 102875
TIME 0900
ADSORBENT LS
ON-SITE SOLIDS ANALYSES
ASH (tfT %) 29.58
CA (NT «) 32.78
S02 (NT ft) 20.53
S03 (NT %) 3.06
C02 (NT %) 10.10
TVA SOLIDS CHARACTERIZATION
ASH (NT %, ACID INSOLUBLE) 27.0
CAC03 (HT *t BY IR) 29.2
CAS03 X .5 H20 (HT %• IR) 38.7
CAS04 X 2H20 (NT *. IR) 5.1
SURFACE AREA (SO M/GM) 2.4
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS % 21.9
SETTLED * SOLIDS 45.2
SCTTLED BUCK DENSITY (GM/CCI 1.35
SETTI ING RATE (CM/HR) 3.6
TVA CRYSTAU-OGRAPHIC ANALYSES
SULFITE REFRACTIVE INDEX 1.590
SUtFITE A AXIS 9.802
STO. ERROR 0.005
SULFITE 8 AXIS 10.683
STD. ERROR 0.005
SULFITE C AXIS 6.506
STO. ERROR 0.004
SCRUBBER OPERATIONAL PARAMETERS
% SOLID OXIDATION 10.60
SAT. RATIO (RADIAN 50 C.) 0.19
STOIC. RATIO 1.63
SLURRY PH 5.82
SLURRY TEMPERATURE (d 51.0
MAKE/PASS (MOLES/THOUS GAL) 86.6
LIO/GAS (GAL/THOUS CFM) 40.0
HT * CL IN LIQUOR 0.30
NT % MG IN LIQUOR 0.04
HOLD TANK RES. TIME (MINS) 12.0
2816
110675
0700
LS
30.68
29.27
23.13
4.48
6.73
33.0
18.5
39.3
8.2
3.0
15.2
38.7
1.28
5.7
1.589
9.774
0.007
10.690
0.006
6.518
0.004
13.40
0.39
1.25
5.66
52.0
88.6
40.2
0.25
0.44
12.0
2816
111375
0700
LS
26.88
30.71
19.59
5.01
11.75
25.0
30.1
35.4
10.0
3.0
15.4
43.8
1.36
6.7
1.593
9.799
0.004
10.683
0.004
6.508
0.003
16.90
0.32
1.49
6.15
52.0
99.1
39.5
0.17
0.04
12.0
2816
111875
0700
LS
43.03
24.18
22.93
3.78
1.35
40.0
2.0
48.1
13.8
3.3
13.8
41.0
1.29
7.5
1.592
9.790
0.004
10.665
0.004
6.510
0.003
11.60
0.10
1.06
5.25
50.0
63.6
40.2
0.21
0.03
12.0
2816
112875
0700
LS
30.82
28.89
20.98
7.35
5.55
24.0
9.8
54.2
11.0
3.7
14.0
34.0
1.27
4.8
1.590
9.779
0.003
10.665
0.004
6.510
0.002
21.90
0.67
1.22
5.95
51.0
84.0
41.2
0.29
0.05
14.8
2816
120775
0700
LS
30.51
30.57
20.82
4.36
8.69
30.0
19.7
43.9
6.4
2.8
15.7
42.8
1.34
6.3
1.590
9.789
0.002
10.662
0.003
6.495
0.002
14.30
0.26
1.43
6.02
50.0
84.1
40.9
0.24
0.05
14.8
2816
121475
0700
LS
46.02
21.48
21.54
4.38
1.24
27.0
4.8
55.5
12.7
1.6
15.5
41.6
1.31
8.0
1.591
9.794
0.005
10.670
0.006
6.506
0.003
14.00
0.83
0.98
5.49
52.0
64.5
41.1
0.17
0.05
14.8
2816
122575
0700
LS
42.82
24.70
22.56
2.81
2.79
32.0
17.6
44.1
6.8
2.5
14.2
42.0
1.33
4.3
1.593
9.785
0.004
10.661
0.005
6.504
0.003
9.08
1.12
1.14
5.79
50.0
64.0
39.1
0.20
0.05
10.8
2816
010176
0700
LS
44.01
24.65
16.98
5.43
4.46
42.0
8.1
42.4
7.5
3.5
14.9
38.7
1.29
6.3
1.590
9.783
0.002
10.666
0.002
6.519
0.001
20.40
1.11
1.32
5.74
52.0
75.5
40.2
0.31
0.04
10.8
2816
011076
0700
LS
46.16
23.16
19.01
5.59
1.39
47.0
2.3
43.8
6.9
2.7
16.2
39.2
1.28
5.4
0.0
9.786
0.003
10.677
0.004
6.515
0.002
19.00
1.15
1.13
5.48
50.0
56.7
41.0
0.39
0.06
14.8
2816
011676
0730
LS
41.33
24.89
24.28
3.52
1.17
32.5
4.4
5!. 8
11.3
3.6
14.7
39.8
1.26
6.9
1.592
9.816
0.005
10.649
0.005
6.523
0.003
10.40
0.95
1.05
5.49
50.0
71.9
41.1
0.32
0.06
14.8
2816
012376
0700
LS
41.74
25.98
21.58
2.20
4.66
29.2
14.2
47.4
9.2
3.1
14.4
37.0
1.26
6.0
1.591
9.800
0.003
10.674
0.003
6.511
0.002
7.54
0.69
1.27
5.81
50.0
96.0
41.1
0.34
0.05
14.8
2816
020176
0730
LS
45.12
22.05
16.72
8.64
1.37
44.5
1.*
47.3
6.8
3.3
15.7
44.6
1.32
7.7
1.591
9.795
0.004
10.674
0.005
6.515
0.003
29.20
1.12
1.06
5.16
50.0
56.0
41.0
0.24
0.04
10.8
-------
TABLE 1. TCA SLURRY ANALYSES
RUN NUMBER 58 1-3 A
ANALYSIS POINT 2816
DATE 020876
TIME 0730
ADSORBENT |_S
ON-SITE SOLIDS ANALYSES
ASH
-------
TABLE 1. TCA SLURRY ANALYSES
RUN NUMBER 586-2A 587-2A 587-2A 588-2* 589-2A 601-3* 601-2A 603-2A 604-2A 604-2A 605-2A 606-2A 607-2A
ANALYSIS POINT 2816
2816
2816
2816
2816
2816
2816
2816
2816
2816
2816
2816
2816
DATE 052276 060176 061076 061976 062876 070476 071076 072176 072976 080376 081276 081876 082376
TIKE 0730
ADSORBENT |_S
ON-SITE SOLIDS ANALYSES
ASH (WT %) 46.32
CA (WT 9) 24.50
S02 (WT ») 17.37
S03 (WT »> 2.36
C02 (WT *> 6.16
TVA SOLIDS CHARACTERIZATION
ASH (MT %» ACID INSOLUBLE) 40.0
CAC03 (WT %» BY IR) 16.0
CAS03 X .5 H20 (WT ttt IR) 35.0
CAS04 X 2H20 (WT *. IR) 8.0
SURFACE AREA (SO M/GM) 2.7
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS % 15.6
~ SETTLED % SOLIDS 42.3
o> SETTLED BULK DENSITY (GM/CC) 1.31
SETTLING RATE (CM/MR) 3.5
TVA CRYSTALL06RAPHIC ANALYSES
SULF1TE REFRACTIVE INDEX 1.589
SULF1TE A AXIS 9.802
STD. ERROR 0.003
SULFITE B AXIS 10.663
STD. ERROR 0.003
SULFITE C AXIS 6.513
STD. ERROR 0.002
SCRUBBER OPERATIONAL PARAMETERS
« SOLID OXIDATION 9.80
SAT. RATIO (RADIAN 50 C.) 0.71
STOIC. RATIO 1.45
SLURRY PH 5.16
SLURRY TEMPERATURE (C) SO.O
MAKE/PASS (MOLES/THOUS GAL) 58.7
LIQ/GAS (GAL/THOUS CFM) 40.0
WT % CL IN LIQUOR 0.39
WT * MG IN LIQUOR 0.82
HOLD TANK RES. TIME (MINS) 3.0
0730
LS
52.77
26.62
8.68
0.01
12.04
45.0
33.0
12.0
10.0
4.1
10.5
25.8
1.17
2.5
1.589
9.803
0.004
10.649
0.004
6.484
0.002
0.10
0.16
3.49
5.94
50.0
86.0
40.0
0.03
0.75
3.0
0730
LS
40.82
26.76
10.47
10.69
5.99
33.0
3.0
56.0
8.0
5.7
10.1
34.0
1.28
5.6
1.587
9.793
0.002
10.677
0.003
6.497
0.002
44.90
1.43
1.60
4.98
51.0
90.9
41.0
0.20
1.02
4.1
0730
LS
39.27
29.03
9.91
5.71
12.55
30.0
36.0
20.0
14.0
4.8
15.2
42.8
1.36
3.0
1.587
9.785
0.003
10.668
0.004
6.529
0.002
31.50
1.15
2.28
5.43
50.0
55.0
60.1
0.51
1.13
4.1
0730
LS
36.93
27.04
18.03
6.82
5.67
30.0
11.0
48.0
11.0
5.6
15.1
32.0
1.26
2.4
1.588
9.803
0.002
10.667
0.002
6.513
0.001
23.20
1.06
1.31
5.32
56.0
97.6
40.7
0.14
1.11
4.1
0730
LIME
38.82
26.92
22.99
5.76
0.57
30.0
0.0
60.0
10.0
6.1
9.5
43.0
1.30
42.6
1.574
9.782
0.003
10.675
0.003
6.511
0.002
16.70
0.79
1.11
6.04
50.0
72.6
41.6
0.11
0.15
4.1
0730
LIME
50.47
20.73
19.92
3.93
0.56
35.0
5.0
52.0
8.0
5.8
9.5
50.8
1.22
50.0
1.574
9.786
0.002
10.679
0.002
6.507
0.001
13.60
0.93
1.02
7.07
52.0
63.2
45.5
0.16
0.27
4.1
0730
LIME
55.49
18.63
17.73
3.69
0.49
45.0
0.0
40.0
15.0
5.2
9.2
43.0
1.35
3.4
1.586
9.783
0.004
10.691
0.004
6.501
0.003
14.30
0.83
1.02
6.64
53.0
57.4
40.9
0.29
0.30
4.1
0730
LIME
46.14
23.12
18.53
7.13
0.05
30.0
0.0
59.0
11.0
6.5
8.5
46.9
1.34
32.2
1.585
9.789
0.003
10.671
0.003
6.514
0.002
23.50
0.83
1.08
6.82
50.0
120.5
31.6
0.35
0.34
4.1
0730
LIME
33.19
25.15
18.88
13.64
0.27
40.0
0.0
50.0
10.0
6.8
10.1
48.6
1.27
33.2
1.580
9.786
0.002
10.688
0.002
6.506
0.001
36.60
0.94
0.96
6.94
51.0
104.0
30.8
0.30
0.30
4.1
0730
LIME
28.24
29.75
28.23
6.64
0.46
25.0
4.0
61.0
10.0
6.3
7.7
39.5
1.30
30.9
1.5B7
9.789
0.002
10.656
0.003
6.512
0.002
15.80
0.33
1.01
0.0
50.0
10.3
60.2
0.26
0.33
4.1
0730
LIME
53.08
20.33
18.36
3.94
0.43
45.0
1.0
45.0
9.0
8.1
8.5
44.9
1.32
42.6
1.590
9.786
0.003
10.683
0.003
6.506
0.002
14.60
0.86
1.07
7.93
52.0
106.3
30.9
0.27
0.32
0.0
0730
LIME
45.10
23.60
18.08
7.44
0.65
35.0
3.0
46.0
16.0
7.1
9.1
47.1
1.33
32.6
1.586
9.774
0.002
10.694
0.002
6.511
0.001
24,70
0,93
1.12
7.90
54.0
95.3
30.7
0.25
0.51
0.0
-------
TABLE 1. TCA SLURRY ANALYSES
RUN NUMBER 608-2A
ANALYSIS POINT 2616
DATE 090476
TIME 0730
AOSORBENT LIME
ON-SITE SOLIDS ANALYSES
ASH (WT *> 34.47
CA (WT «) 26.97
S02 (WT «> 24.61
503 (WT *> 6.53
C02 (WT %> 1.15
TVA SOLIDS CHARACTERISATION
ASH (WT «. ACID INSOLUBLE) 35.0
CAC03 (WT %. BY IR) 2.0
CAS03 X .5 H20 (WT %. IR) 54.0
CAS04 X 2H20 (WT *t IR) 10.0
SURFACE AREA (SO M/GM) 7.8
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS % 16.3
SETTLED * SOLIDS 47.6
SETTLED BULK DENSITY (GM/CC) 1.38
SETTLING RATE < CM/MR > 37.2
TVA CRYSTALLOGRAPHIC ANALYSES
SULFITE REFRACTIVE INDEX 1.581
SULFITE A AXIS 9.782
STO. ERROR 0.002
SULFITE 8 AXIS 10.675
STD. ERROR 0.002
SULFITE C AXIS 6.512
STO. ERROR 0.001
SCRUBBER OPERATIONAL PARAMETERS
% SOLID OXIDATION 17.50
SAT. RATIO (RADIAN 50 C.) 1.11
STOIC. RATIO 1.03
SLURRY PH 7.85
SLURRY TEMPERATURE (C) 54.0
MAKE/PASS (MOLES/THOUS GAL) 124.8
LIO/GAS (GAL/TMOUS CFM) 30.5
WT * CL IN LIQUOR 0.25
WT % MG IN LIQUOR 0.50
HOLD TANK RES. TIME (MINS) o.o
608-2A
2816
090976
0730
LIME
34.17
27.42
25.69
5.38
1.43
30.0
3.0
56.0
11.0
7.2
16.2
45.0
1.37
8.6
1.585
9.794
0.004
10.664
0.004
6.486
0.003
14.30
0.08
1.04
7.96
50.0
127.7
30.4
0.28
0.52
0.0
609-2A
2816
091576
0730
LIME
47.22
24.09
22.57
2.08
0.75
45.0
0.0
45.0
10.0
4.6
10.9
53.0
1.33
26.9
1.587
9.800
0.003
10.674
0.003
6.503
0.002
6.87
0.18
1.14
6.99
53.0
132.9
30.8
0.36
0.38
0.0
609-2A
2816
092276
0730
LIME
34.87
26.79
24.81
6.81
0.41
45.0
1.0
46.0
8.0
3.9
7.9
45.2
1.38
52.6
1.582
9.786
0.002
10.652
0.002
6.511
0.001
18.00
0.55
1.01
6.84
53.0
103.1
31.2
0.34
0.33
5.4
6 10-2 A
2816
092976
0730
LIME
40.10
26.79
27.03
1.48
0.76
25.0
3.0
62.0
10.0
5.2
7.8
41.7
1.36
52.1
1.585
9.793
0.003
10.666
0.003
6.501
0.002
4.20
0.12
1.08
7.68
53.0
117.6
31.0
0.30
0.33
5.4
610-2A
2816
100676
0730
LIME
50.89
22.48
22.44
0.88
0.47
35.0
2.0
49.0
14.0
4.0
7.7
43.4
1.33
67.2
1.582
9.768
0.002
10.665
0.002
6.514
0.002
3.00
0.82
1.10
7.95
50.0
103.4
30.6
0.41
0.35
4.1
611-2A
2816
101076
0730
LIME
38.38
24.95
16.64
12.19
0.60
35.0
3.0
41.0
22.0
7.5
9.0
40.2
1.33
39.2
1.583
9.796
0.003
10.677
0.004
6.505
0.002
36.90
0.95
1.07
8.08
49.0
102.5
30.8
0.55
0.43
4.1
613-2A
2816
102076
0730
LIME
42.50
23.13
15.56
11.24
0.77
40.0
0.0
31.0
29.0
8.2
9.2
42.0
1.33
34.8
1.581
9.779
0.004
10.676
0.004
6.520
0.003
36.60
0.86
1.07
6.74
54.0
87.8
41.5
0.56
0.44
3.0
614-2A
2816
102776
0730
LIME
39.34
27.62
25.41
2.89
0.83
30.0
0.0
58.0
12.0
5.6
7.9
38.7
1.29
36.6
1.587
9.779
0.003
10.675
0.003
6.508
0.002
8.30
0.80
1.14
8.08
48.0
123.3
31.0
0.44
0.35
16.0
616-2A
2816
110676
0730
LIME
51.44
22.32
20.45
1.50
1.43
38.0
6.0
43.0
14.0
5.9
9.1
38.7
1.31
33.8
1.582
9.757
0.002
10.670
0.003
6.507
0.002
5.50
0.89
1.17
8.32
53.0
74.9
40.8
0.25
0.02
12.0
616-2A
2816
111176
0730
LIME
42.90
23.20
19.45
7.59
0.89
40.0
2.0
48.0
10.0
6.8
7.8
46.4
1.35
67.8
1.585
9.781
0.002
10.660
0.002
6.514
0.001
23.70
1.29
1.03
5.74
51.0
76.8
40.8
0.47
0.03
12.0
617-2A
2816
111776
0730
LIME
40.69
25.27
22.44
5.22
1.26
25.0
s.o
59.0
11.0
4.6
20.2
57.1
1.36
9.4
0»0>
9.773
0.002
10.653
0.002
6.514
0.001
15.60
1.06
1.08
8.00
50.0
80.9
40.6
0.39
0.05
12.0
701-2A
2816
112676
0730
LS
5.19
43.10
36.55
5.06
3.91
5.0
18.0
63.0
14. 0
*.o
7.6
24.9
1.19
5.4
0.0
9.793
0.002
10.663
0.002
6.509
0.001
9.90
0.81
1.21
5.64
50.0
72.3
40.2
0.35
0.02
4.1
-------
TABLE 1. TCA SLURRY ANALYSES
CO
RUN NUMBER TO 1-2 A
ANALYSIS POINT 2816
DATE 113076
TIME 0730
ADSORBENT LS
ON-SITE SOLIDS ANALYSES
ASM (WT *> 3.12
CA (WT ft) 41.30
S02 (WT X) 27.87
S03 (WT »> 14.13
C02 (WT *) 4.23
TVA SOLIDS CHARACTERIZATION
ASH (WT ». ACID INSOLUBLE) 5.0
CACO3 (WT Ct BY IR) 16.0
CAS03 X .5 H20 (WT *t IR) 60.0
CAS04 X 2H20 (WT %» IR) 19.0
SURFACE AREA (SO M/GM) 5.2
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS * 8.3
SETTLED » SOLIDS 24.4
SETTLED BULK DENSITY (6M/CC) 1.18
SETTLING RATE (CM/HR) 4.8
TVA CRYSTALL06RAPHIC ANALYSES
SULFITE REFRACTIVE INDEX 0.0
SULFITE A AXIS 9.781
STD. ERROR 0.002
SULFITE 8 AXIS 10.664
STD. ERROR 0.002
SULFITE C AXIS 6.514
STO. ERROR 0.001
SCRUBBER OPERATIONAL PARAMETERS
% SOLID OXIDATION 20.00
SAT. RATIO (RADIAN 50 C.) 1.07
STOIC. RATIO 1.20
SLURRY PH 5.57
SLURRY TEMPERATURE (C) 53.0
MAKE/PASS (MOLES/THOUS GAL) 64.7
LIO/GAS (GAL/THOUS CFM) 40.6
WT % CL IN LIOUOR 0.27
WT « MG IN LIQUOR 0.04
HOLD TANK RES. TIME (MINS) 4.1
702-2A
2816
120976
0730
LS
10.01
40.37
41.21
0.25
2.85
0.0
14.0
71.0
14.0
2.1
15.1
41.4
1.31
5.4
0.0
9.794
0.002
10.670
0.002
6.493
0.001
0.40
0.17
1.11
5.70
50.0
77.1
40.7
0.37
0.08
0.0
703-2A
2816
121676
0730
LS
12.04
38.42
33.29
5.93
3.57
0.0
10.0
80.0
11.0
2.2
7.7
33.1
1.23
13.8
0.0
9.791
0.002
10.655
0.002
6.502
0.001
12.40
0.21
1.15
5.66
49.0
88.4
41.0
0.36
0.05
0.0
704-2A
2816
122376
0730
LS
7.32
41.84
41.62
0.81
2.97
0.0
13.0
73.0
14.0
2.4
8.2
33.7
1.24
17.1
0.0
9.794
0.003
10.669
0.003
6.496
0.002
1.50
0.31
1.13
5.77
50.0
61.3
40.4
0.36
0.06
0.0
704-2A
2816
123076
0730
LS
3.48
43.81
36.55
6.66
2.86
0.0
10.0
77.0
13.0
2.4
8.0
37.5
1.22
10.9
0.0
9.773
0.004
10.671
0.004
6.502
0.002
11.80
0.47
1.20
5.71
52.0
86.6
40.9
0.31
0.06
12.0
705-2A
2816
010777
0730
LS
13.04
38.81
32.45
5.27
4.29
3.0
21.0
63.0
13.0
2.3
15.9
38.9
1.27
5.5
0.0
9.791
0.002
10.682
0.003
6.507
0.002
11.50
1.44
1.20
5.91
50.0
76.9
40.8
0.24
0.06
12.0
705-2A
2816
011277
0730
LS
9.36
40.88
38.00
2.67
3.41
0.0
11.0
82.0
6.0
1.8
15.2
41.6
1.30
5.6
0.0
9.788
0.002
10.652
0.002
6.500
0.001
5.30
0.32
1.16
5.86
50.0
80.7
41.0
0.35
0.06
12.0
706-2A
2816
012277
0730
LS
0.0
42.54
30.27
12.76
6.57
0.0
16.0
68.0
16.0
2.9
15.2
39.0
1.30
4.0
0.0
9.792
0.002
10.658
0.002
6.512
0.001
25.20
1.01
1.19
5.70
47.0
78.8
41.0
0.32
0.06
12.0
706-1A
2816
012877
0730
LS
16.66
35.44
33.22
4.50
3.52
5.0
7.0
80.0
8.0
2.6
14.5
37.6
1.31
4.5
0.0
9.778
0.002
10.668
0.002
6.513
0.001
9.70
0.16
1.09
5.50
53.0
72.7
40.7
0.27
0.06
12.0
706-2A
2816
020377
0730
LS
4.18
39.49
33.97
8.93
4.46
2.0
7.0
75.0
16.0
2.9
15.4
35.8
1.26
4.6
0.0
9.783
0.003
10.659
0.0.03
6.519
0.002
10.80
1.33
1.18
5.41
48.0
64.1
41.3
0.43
0.07
12.0
TFG-2C
2816
021177
0715
LS
38.90
26.96
21.71
3.97
3.96
35.0
15.0
38.0
11.0
3.7
15.3
40.7
1.33
6.0
0.0
9.784
0.002
10.664
0.002
6.517
0.001
12.70
0.96
1.23
5.71
50.0
95.8
41.1
0.46
0.07
12.0
TFG-2D
2816
021877
0715
LS
31.47
31.08
24.84
4.60
3.33
35.0
9.0
45.0
10.0
3.5
13.9
40.2
1.30
7.0
0.0
9.794
0.002
10.663
0.002
6.508
0.001
12.90
0.79
1.24
5.91
49.0
73.3
61.0
0.02
0.05
12.0
TFG-2F
2816
022477
0715
LS
34.00
28.60
20.99
7.76
2.86
40.0
5.0
48.0
8.0
5.0
15.5
36.3
1.28
*.o
0.0
9.799
0.003
10.660
0.003
6.517
0.002
22.80
0.69
1.20
5.66
53.0
78.6
40.8
0.33
0.05
12.0
-------
TABLE 1. TCA SLURRY ANALYSES
vo
RUN NUMBER TFG-2F
ANALYSIS POINT 2816
DATE 022877
TIME 0715
ADSORBENT LS
ON-SITE SOLIDS ANALYSES
ASH (WT ft) 32.74
CA (WT ft) 29.07
S02 (WT ft) 23.98
S03 (WT ft) 4.81
C02 (WT ft) 4.06
TVA SOLIDS CHARACTERIZATION
ASM (WT ft. ACID INSOLUBLE) 35.0
CAC03 (WT ». BY IR) 9.0
CAS03 X .5 H20 (WT ft* IR) 46.0
CA504 X 2H20 (WT «, IR) 10.0
SURFACE AREA (SO M/GM) 4.7
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS ft 14.3
SETTLED « SOLIDS 35.9
SETTLED BULK DENSITY (9M/CC) 1.27
SETTLING RATE (CM/HR) 5.5
TVA CRYSTALL06RAPHIC ANALYSES
SULFITE REFRACTIVE INDEX 0.0
SULFITE A AX.IS 9.793
STO. ERROR 0.004
SULFITE 8 AXIS 10.672
STD. ERROR 0.005
SULFITE C AXIS 6.511
STD. ERROR 0.003
SCRUBBER OPERATIONAL PARAMETERS
ft SOLID OXIDATION 13.80
SAT. RATIO (RADIAN 50 C.) 0.84
STOIC. RATIO 1.19
SLURRY PH 5.57
SLURRY TEMPERATURE (C) 50.0
MAKE/PASS (MOLES/THOUS GAL) 74.3
LIO/OAS (GAL/THOUS CFM) 40.8
WT « CL IN LIQUOR 0.32
WT ft MG IN LIQUOR 0.06
HOLD TANK RES. TIME (MINS) 12.0
707-2A
2816
030877
0715
LS
39.11
26.86
19.54
5.71
3.97
35.0
12.0
42.0
11.0
4.4
16.3
41.6
1.30
6.4
0.0
9.796
0.003
10.662
0.003
6.520
0.002
18.90
1.47
1.27
5.54
50.0
64.6
41.0
0.41
0.05
4.1
709-2A
2816
031677
0715
LS
42.30
25.00
17.30
5.81
4.75
35.0
16.0
38.0
11.0
2.7
14.9
44.5
1.39
10.5
0.0
9. SOB
0.002
10.667
0.002
6.516
0.002
19.30
1.11
1.33
5.41
50.0
59.8
41.0
0.15
0.03
4.1
710-2A
2816
032277
0715
LS
44.41
24.74
19.54
3.86
3.41
35.0
5.0
50.0
10.0
3.8
15.5
41.6
1.32
6.9
0.0
9.781
0.002
10.657
0.002
6.521
0.001
13.60
1.19
1.24
5.77
53.0
58.5
40.9
0.19
0.04
10.0
711-2A
2816
032877
0715
LS
39.11
28.35
25.25
1.S9
2.3«
30.0
13.0
45.0
12.0
3.1
14.2
40.5
1.33
8.2
0.0
9.782
0.002
10.659
0.002
6.512
0.001
4.80
0.63
1.22
5.62
51.0
68.3
41.4
0.20
0.05
12.0
-------
TABLE 2. VENTURI/SPRAY TOWER SLURRY ANALYSES
RUN NUMBER 623-1A 633-1A 624-1A 62*-1A 627-1A 638-1A 628-18 628-1B 628-18 701-1* 703-1* 703-1A 704-1*
ANALYSIS POINT
DATE
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
031375 031*75 040375 041175 080875 091475 093175 090875 100575 161Z75 103175
1816 1816
102875 110675
TIME 1300
ADSORBENT LIME
ON-SITE SOLIDS ANALYSES
ASH fWT ft) 0.0
CA (WT ft) 0.0
S02 (WT ft) 0.0
SO3 (WT ft) 0.0
C02 (WT ft) 0.0
TVA SOLIDS CHARACTERIZATION
ASH (WT ft* ACID INSOLUBLE) 33.0
CAC03 (WT ft* BY IR) 3.3
CASO3 X .5 H20 (WT ft* IR) 59.0
CASO4 X 2H20 (WT ft. IR) 4.5
SURFACE AREA (SO M/GM) 7.0
TVA SLURRY CHARACTERIZATION
SLURRY SOL I OS ft 8.8
SETTLED ft SOLIDS 38.1
SETTLED BULK DENSITY (OM/CC) 1.32
SETTLING RATE (CM/MR) 12.4
TVA CRYSTALLOGRAPHIC ANALYSES
SULFITE REFRACTIVE INDEX 1.592
SULFITE A AXIS 9.743
STO. ERROR 0.010
SULFITE B AXIS 10.630
STO. ERROR 0.006
SULFITE C AXIS 6.502
STO.. ERROR 0.005
SCRUBBER OPERATIONAL PARAMETERS
ft SOLID OXIDATION 0.0
SAT. RATIO (RADIAN 50 C.) 0.98
STOIC. RATIO 0.0
SLURRY PH 7.90
SLURRY TEMPERATURE (C) 51.0
MAKE/PASS (MOLES/THOUS GAL) 0.0
LIO/6AS (GAL/THOUS CFM) 0.0
WT ft CL IN LIQUOR 0.33
WT ft MG IN LIQUOR 0.02
HOLD TANK RES. TIME (MINS) 17.0
1300
LIME
37.71
26.66
22.08
6.06
2.08
33.0
5.6
53.0
9.0
5.9
7.3
32. 2
1.22
11.5
1.581
9.750
0.012
10.632
0.006
6.495
0.005
18.00
0.71
1.13
7.70
50.0
0.0
0.0
0.31
0.02
17.0
700
LIME
38.46
2S.99
23.11
5.04
2.06
69.0
1.4
27.0
2.0
4.6
11.6
39.1
1.35
8.7
1.584
9.759
0.019
10.619
0.011
6.493
0.010
14.80
0.0
1.09
8.80
50.0
0.0
0.0
0.0
0.0
17.0
1145
LIME
0.0
0.0
0.0
0.0
0.0
45.0
5.0
45.0
7.2
3.0
7.9
46.4
1.45
13.9
1.590
9.799
0.035
10.665
0.019
6.498
0.018
0.0
1.17
0.0
0.0
0.0
0.0
0.0
0.43
0.02
17.0
1220
LIME
45.30
24.34
17.24
5.14
3.76
40.0
10.2
38.4
11.4
8.1
15.6
34.0
1.24
2.4
1.593
9.769
0.003
10.729
0.004
6.510
0.004
19.30
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
20.0
0700
LIME
39.58
24.81
20.76
6.92
1.97
35.0
8.3
43.3
13.4
4.1
8.7
44.9
1.30
38.4
1.590
9.776
0.006
10.636
0.006
6.531
0.005
21.00
1.03
1.08
7.95
52.0
40.6
90.4
0.31
0.03
12.0
0700
LIME
39.23
2S.32
22.08
5.88
1.88
40.0
6.5
47.6
5.8
4.3
9.4
39.6
1.28
35.6
1.590
9.775
0.006
10.673
0.006
6.521
0.005
17.60
0.84
1.08
8.25
53.0
41.8
97.4
0.33
0.03
12.0
0700
LIME
39.62
24.63
21.98
4.11
4.19
41.5
3.9
44.8
9.8
5.1
25.7
42.1
1.31
2.1
1.589
9.764
0.010
10.678
0.010
6.514
0.007
13.00
0.69
1.11
8.10
50.0
49.4
82.9
0.37
0.02
12.0
0700
LIME
39.22
24.81
23.19
5.15
1.90
33.0
3.7
53.1
10.2
4.1
9.5
44.5
1.26
20.5
1.588
9.778
0.003
10.667
0.003
6.518
0.003
15.10
0.73
1.04
7.95
52.0
53.6
68.8
0.44
0.03
12.0
0700
LS
27.70
32. OS
19.86
7.19
7.54
27.0
21.1
44.8
7.1
3.4
18.4
37.0
1.27
2.5
1.589
9.798
0.005
10.690
O.OOS
6.506
0.004
22.40
0.23
1.43
5.85
54.0
50.1
69.2
0.49
0.05
20.0
0700
LS
44.62
23.00
21.60
4.10
1.76
45.0
2.8
45.0
7.2
2.2
10.2
44.7
1.29
9.6
1.590
9.769
0.006
10.690
0.005
6.519
0.004
13.20
0.0
1.06
5.25
50.0
0.0
63.7
0.0
0.0
20.0
0900
LS
43.15
24.34
22.07
3.44
2.47
45.0
6.0
41.0
8.0
1.8
12.8
45.5
1.36
7.8
1.590
9.799
0.006
10.680
0.006
6.527
0.005
11.10
0.71
1.13
5.31
51.0
42.2
63.6
0.67
0.07
20.0
0700
LS
30.27
33.49
20.95
2.64
9.31
27.0
30.9
34.8
7.3
2.5
16.4
1.34
4.3
1.591
9.795
0.006
10.683
0.006
6.511
0.005
9.20
0.12
1.66
5.84
52.0
70.0
64.3
0.5*
0.11
20.0
LS = Limestone
-------
TABLE 2. VENTURI/SPRAY TOWER SLURRY ANALYSES
RUN NUMBER 705-1 A
ANALYSIS POIVT 1816
DATE 111376
TIME 0700
ADSORBENT LS
ON-SITE SOLIDS ANALYSES
ASH (WT *) 34.81
CA (WT «) 37.43
S02 (WT *) 23.80
S03 (WT *) 1.59
C02 (WT «> 7.47
TVA SOLIDS CHARACTERIZATION
ASH (WT *. ACID INSOLUBLE) 35.0
CAC03 (WT «, BY IR) 16.4
CAS03 X .5 H20 (WT %. IR) 40.1
CAS04 X 2H20 (WT %» IR) 8.4
SURFACE ARC A (SQ M/GM) 1.8
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS « 14.5
SETTLED % SOLIDS 50.3
SETTLED BULK DENSITY (GM/CC) 1.33
SETTLING RATE (CM/HR) 9.0
TVA CRYSTALL06RAPHIC ANALYSES
SULFITE REFRACTIVE INDEX 1.591
SULFITE A AXIS 9.781
STD. ERROR 0.005
SULFITE B AXIS 10.679
STD. ERROR 0.004
SULFITE C AXIS 6.509
STD. ERROR 0.003
SCRUBBER OPERATIONAL PARAMETERS
% SOLID OXIDATION 5.10
SAT. RATIO (RADIAN 50 C.) 0.25
STOIC. RATIO 1.25
SLURRY PH 6.00
SLURRY TEMPERATURE (C<> 52.0
MAKE/PASS (MOLES/THOUS GAL) 61.1
LIO/GAS (GAL/THOUS CFM) 67.0
WT * CL IN LIOUOR 0.34
WT % MG IN LIQUOR 0.06
HOLD TANK RES. TIME (MINS) 20.0
706-1A
1816
111975
0700
LS
42.00
23.99
23.25
4.12
1.47
40.0
2.0
48.1
10.0
2.2
12.6
40.6
1.40
8.5
1.592
9.790
0.010
10.691
0.006
6.534
0.005
12.40
1.11
1.03
5.25
50.0
47.1
63.9
0.37
0.07
12.0
708-1 A
1816
112775
0700
LS
31.63
29.27
20.17
6.31
6.84
27.0
11.1
54.1
7.8
2.2
14.4
44.6
1.34
4.5
1.590
9.790
0.003
10.657
0.004
6.503
0.002
21.30
0.57
1.30
s.es
51.0
47.5
63.9
0.45
0.09
12.0
709-1A
1816
120775
0700
LS
37.84
26.88
20.56
4.66
5.12
30.0
13.4
47.5
9.1
2.5
15.2
43.5
1.31
3.6
1.592
9.785
0.002
10.673
0.002
6.505
0.001
15.30
0.57
1.26
5.71
51.0
53.0
63.9
0.42
0.09
12.0
T10-IA
1816
121475
0700
LS
34.35
28.54
20.43
3.72
8.09
32.0
22.4
39.5
6.1
2.3
16.4
43.5
1.32
3.9
1.595
9.797
0.003
10.660
0.003
6.492
0.002
12.73
0.15
1.39
6.03
55.0
63.3
63.1
0.37
O.OB
12.0
710-1A
1016
122275
0700
LS
38.27
26.71
24.50
1.82
4.31
42.0
12.4
41.5
9.1
1.9
16.3
43.2
1.34
4.6
1.594
9.788
0.002
10.667
0.003
6.501
0.002
5.62
0.23
1.18
5.83
52.0
63.9
64.1
0.37
0.09
12.0
711-18
1816
010176
0700
LS
38.87
27.41
17.94
4.43
7.04
37.0
15.2
39.1
8.7
3.1
16.0
40.8
1.29
3.4
1.591
9.800
0.004
10.665
0.004
6.515
0.002
16.50
0.90
1.46
5.57
52.0
58.3
63.7
0.56
0.07
6.0
713-1A
1816
010976
0700
LS
49.98
22.47
17.87
4.08
1.93
43.0
6.8
41.9
8.3
2.9
15.0
41.8
1.30
4.8
1.590
9.791
0.002
10.673
0.002
6.519
0.001
15.40
1.17
1.21
5.14
48.0
49.6
64.2
0.55
O.OB
6.0
1816
012276
0700
LS
34.98
28.28
22.95
3.42
5.56
35.5
11.9
4*. 7
7.9
3.1
17.2
41.6
1.30
2.8
1.591
9.795
0.003
10.660
0.004
6.517
0.002
10.60
1.11
1.26
5.50
50.0
52.5
65.6
0.44
0.46
6.0
717-1A
1816
013176
0730
LS
36.41
27.46
22.49
4.79
3.74
39.0
5.6
50.3
5.1
2.3
15.9
42.7
1.30
3.6
1.591
9.806
0.003
10.665
0.003
6.511
0.002
14.50
0.64
1.19
5.53
50.0
53.8
64.1
0.34
0.43
6.0
FACT.
1816
021576
0730
LIME
33.06
28.70
22.62
7.64
1.98
34.5
4.7
53.8
7.0
5.2
17.2
50.9
1.29
6.3
1.590
9.786
0.003
10.653
0.003
6.450
0.002
21.30
0.54
1.14
7.93
50.0
41.0
85.0
0.49
0.05
12.0
FACT.
1816
022176
0730
LIME
55.91
19.16
13.71
6.04
1.16
61.0
5.3
27.7
6.0
5.0
16.6
55.6
1.37
8.7
1.586
9.774
0.004
10.652
0.004
6.501
0.002
26.10
1.22
1.18
8.13
51.0
33.2
43.6
0.88
0.04
0.0
FACT.
1816
030276
0730
LIME
56.99
20.36
16.45
2.56
1.17
45.0
3.0
40.0
13.0
5.0
16.1
46.9
1.35
5.8
1.585
9.773
0.004
10.650
0.004
6.511
0.002
11.10
1.19
1.23
8.18
50.0
68.6
5.3
1.22
0.06
6.0
-------
TABLE 2. VENTURI/SPRAY TOWER SLURRY ANALYSES
RUN NUMBER FACT.
ANALYSIS POINT 1816
DATE 030676
TIME 0730
ADSORBENT LS
ON-SITE SOLIDS ANALYSES
ASH (WT ») 41.73
CA (WT «) 27.5e
SO? (WT *) 19.19
S03 (WT %) 2.95
C02 (WT %) 5.37
TVA SOLIDS CHARACTERIZATION
ASH (WT «• ACID INSOLUBLE) 33.0
CAC03 (WT ft. BY IPO 13.0
CAS03 X .5 H20 (WT %. IR) 43.0
CAS04 X 2H20 (WT *. IR> 11.0
SURFACE AREA (SO M/GM) 5.3
TVA SLURRY CHARACTERIZATION
SLW»RY SOLIDS % 15.5
SETTLED » SOLIDS 44.4
SETTLED BULK DENSITY (GM/CC) 1.35
SETTLING RATE
-------
TABLE 2. VENTURI/SPRAY TOWER SLURRY ANALYSES
RUN NUMBER 634-1 A
ANALYSIS POINT 1816
DATE 062776
TIME 0730
ADSORBENT LIME
ON-SITE SOLIDS ANALYSES
ASH (WT *> 2.44
CA (WT %) 40.97
SO2 (WT *) 34.54
S03 (WT «) 10.23
C02 (WT ») 2.82
TVA SOLIDS CHARACTERIZATION
ASH (WT %« ACID INSOLUBLE) 1.0
CACO3 (WT %» BY IR) 8.0
CAS03 X .5 H20 (WT %, IR) 80.0
CAS04 X 2H2O (WT %, IR) 12.0
SURFACE AREA (SQ M/GM) 7.1
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS * 4.5
SETTLED * SOLIDS 40.6
SETTLED BULK DENSITY (GM/CC) 1.21
SETTLING RATE (CM/HR) 90.0
TVA C«YST ALLOGRAPH 1C ANALYSES
SULFITE REFRACTIVE INDEX 1.595
SULFITE A AXIS 9.764
STO. ERROR 0.002
SULFITE B AXIS 10.656
STD. ERROR 0.002
SULFITE C AXIS 6.508
STO. ERROR 0.001
SCRUBBER OPERATIONAL PARAMETERS
ft SOLID OXIDATION 19.10
SAT. RATIO (RADIAN 50 C.) 1.19
STOIC. RATIO 1.09
SLURRY PH 7.94
SLURRY TEMPERATURE (CJ 53.0
MAKE/PASS (MOLES/THOUS GAL) 39.8
LIQ/GAS (GAL/THOOS CFM) 64.0
MT % CL IN LIQUOR 0.37
MT * MG IN LIQUOR 0.06
HOLD TANK RES. TIME (MINS) 12.0
718-1A
1816
070376
0800
LIME
4.60
38.71
25.00
19.04
1.47
1.0
6.0
66.0
28.0
4.4
4.5
37.2
1.31
67.7
1.593
9.766
0.002
10.670
0.002
6.502
0.001
37.80
1.09
1.09
5.33
50.0
22.6
111.0
0.44
0.04
12.0
718-1A
1816
071176
0730
LS
0.0
47.23
31.12
17.05
5.50
1.0
14.0
66.0
20.0
4.6
9.2
30.9
1.22
4.6
1.586
9.792
0.003
10.675
0.003
6.506
0.002
30.40
1.16
1.20
5.87
53.0
38.7
63.0
0.48
0.06
12.0
635-1 A
1816
072076
0730
LIME
10.90
39.53
34.69
4.76
3.82
1.0
10.0
83.0
7.0
10.4
9.4
36.0
1.19
8.4
1.580
9.767
0.002
10.633
0.002
6.510
•0.001
9.80
0.44
1.17
8.65
52.0
37.6
63.1
0.42
0.05
12.0
635-1A
1816
072676
0730
LIME
0.0
42.41
28.15
19.35
2.94
1.0
9.0
78.0
13.0
7.4
9.0
36.6
1.31
10.9
1.582
9.77*
0.002
10.645
0.003
6.504
0.002
35.40
1.00
1.11
7.95
53.0
44.1
63.5
0.45
0.07
12.0
636-1A
1816
080176
0730
LIME
2.23
42.72
35.47
8.84
2.80
1.0
12.0
75.0
13.0
10.3
10.3
42.4
1.21
8.7
1.585
9.736
0.002
10.663
0.002
6.511
0.001
16.60
0.99
1.14
7.87
50.0
36.2
89.3
0.44
0.07
12.0
637-1A
1816
081176
0730
LIME
0.41
44.80
37.39
8.21
1.87
1.0
7.0
83.0
11.0
6.3
8.6
39.6
1.25
28.2
1.584
9.773
0.003
10.653
0.003
6.513
0.002
14.90
0.97
1.08
7.96
50.0
37.7
74.3
0.36
0.06
12.0
638-1A
1816
081776
0730
LIME
0.0
40.36
36.54
10.91
2.44
1.0
7.0
80.0
13.0
5.6
5.0
40.7
1.30
87.0
1.600
9.772
0.003
10.646
0.0*3
6.515
0.002
19.20
1.18
1.01
7.91
52.0
42.8
63.7
0.29
0.06
3.0
639-1A
1816
082576
0730
LIME
0.0
41.02
41.98
7.05
2.10
1.0
5.0
88.0
7.0
8.9
5.5
37.8
1.22
46.1
1.590
9.797
0.002
10.647
0.003
6.495
0.002
11.80
0.05
0.98
6.99
54.0
44.4
63.7
0.35
0.28
3.0
640-1*
1816
090576
0730
LIME
3.12
41.69
38.62
7.46
1.14
1.0
4.0
82.0
14.0
5.4
10.8
53.9
1.31
31.3
1.583
9.791
0.003
10.672
0.003
6.513
0.002
13.30
0.75
1.06
6.87
54.0
51.4
64.3
0.34
0.30
3.0
641-1*
1816
091076
0730
LIME
0.0
45.37
39.42
12.47
1.52
1.0
2.0
86.0
12.0
5.6
8.3
41.9
1.25
34.9
1.580
9.781
0.003
10.662
0.003
6.511
0.002
20.20
0.36
1.04
7.04
54.0
48.6
45.1
0.55
0.40
3.0
642-1 A
1816
091676
0730
LIME
14.17
36.14
36.73
5.40
0.32
1.0
1.0
88.0
12.0
5.0
8.2
40.8
1.30
22.3
1.585
9.788
0.003
10.659
0.003
6.514
0.002
10.50
0.61
1.01
6.55
53.0
61.4
34.9
0.54
0.36
3.0
642-1*
1816
092376
0730
LIME
1.97
41.40
37.82
9.37
0.64
1.0
2.0
84.0
14.0
4.6
8.1
40.2
1.29
32.2
1.562
9.789
0.002
10.666
0.002
6.511
0.001
16.50
0.84
1.04
6.94
52.0
60.2
34.8
0.64
0.44
3.0
-------
TABLE 2. VENTURI/SPRAY TOWER SLURRY ANALYSES
RUN NUMBER 643-U 6*3-1* VFG-001 VFO-1B VFG-1B VFG-1D VF6-1F VFS-lf VF6-1I VFO-1P 801-1* 801-1* 802-U
ANALYSIS POINT 1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
DATE 092876 100476 101176 102176 102876 110576 111276 111676 112576 120176 010877 011177 012777
TJME 0730
ADSORBENT LIME
OW-SITE SOLIDS ANALYSES
ASH (WT ») 0.0
CA (WT *) 43.71
S02 (WT *) 39.09
SOS (WT *> 13.19
C02 (WT «> 1.33
TVA SOLIDS CHARACTERIZATION
ASH
-------
TABLE 2. VENTURI/SPRAY TOWER SLURRY ANALYSES
RUN NUMBER
ANALYSIS POINT
DATE
TIME
ADSORBENT
ON-SITE SOLIDS ANALYSES
ASH (NT %)
CA (WT «)
S02 (WT *>
S03 (MT «>
C02 (NT %)
TVA SOLIDS CHARACTERIZATION
ASH (MT %. ACIO INSOLUBLE)
CAC03 (WT %• BY IR)
CAS03 X .5 H20 (WT »» IR)
CAS04 X 2H20 (WT ft* IR)
SURFACE AREA (SO M/GM)
TVA SLURRY CHARACTERIZATION
SLURRY SOLIDS %
SETTLED % SOLIDS
SETTLED BULK DENSITY (GM/CO
SETTLING RATE (CM/HR)
TVA CRYSTALLOGRAPHIC ANALYSES
SULFITE REFRACTIVE INDEX
SULFITE A AXIS
STD. ERROR
SULFITE B AXIS
STO. ERROR
SULFITE C AXIS
STO. ERROR
SCRUBBER OPERATIONAL PARAMETERS
% SOLID OXIDATION
SAT. RATIO (RADIAN 50 C.)
STOIC. RATIO
SLURRY PH
SLURRY TEMPERATURE (C)
MAKE/PASS (MOLES/THOUS GAL)
LIQ/GAS (6AL/THOUS CFM)
WT % CL IN LIQUOR
WT * MG IN LIQUOR
HOLD TANK RES. TIME
-------
TABLE 2. VENTURI/SPRAY TOWER SLURRY ANALYSES
RUN NUMBER 851-1A 851-1A 853-1A 8S3-1A 854-1* 954-1A
ANALYSIS POINT 1816
1815
1816
1815
1816
1815
DATE 031577 031577 033377 032377 033977 03Z977
TIME 0715
ADSORBENT LIME
ON-SITE SOLIDS ANALYSES
ASH (WT *) 0.0
CA (MT «) 45.41
S02 (WT %) 35.44
S03 (WT %) 10.11
C02 (WT *) 3.14
TVA SOLIDS CHARACTERIZATION
ASH (WT %. ACID INSOLUBLE) 0.0
CAC03 (WT ft* BY IR) 12.0
CAS03 X .5 H20
-------
TABLE 3. SETTLING RATE DETERMINATIONS
Settling rate (cm/h)
Sample ID Muscle Shoals (M)
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
1816
2816
2816
2816
2816
2816
2816
2816
2816
2816
2816
2816
7/18/75
7/24/75
8/04/75
8/18/75
9/02/75
9/30/75
10/15/75
11/04/75
11/13/75
11/19/75
12/17/75
12/30/75
5/04/76
5/17/76
6/21/76
8/01/75
8/26/75
10/08/75
11/26/75
12/03/75
1/07/76
1/19/76
4/27/76
5/12/76
5/24/76
6/02/76
Total
Mean
Std.
Dev.
37.9
34.2
46.0
5.4
34.5
19.0
4.4
9.6
8.8
9.2
4.1
4.4
5.9
16.4
107.1
5.8
4.5
5.5
9.1
6.2
7.0
6.8
2.7
1.2
3.9
2.0
401.6
15.45
-
Shawnee (S)
52.5
47.5
46.9
5.5
32.0
17.6
4.0
13.1
9.3
11.2
4.1
4.3
6.7
22.0
160.0
5.7
5.5
5.6
10.1
5.4
7.0
7.0
2.7
1.7
4.4
3.5
495.3
19.05
-
S-M = Y
14.6
13.3
0.9
0.1
-2.5
-1.4
-0.4
3.5
0.5
2.0
0.0
-0.1
0.8
5.6
52.9
-0.1
1.0
0,1
1.0
-0.8
0.0
0.2
0.0
0.5
0.5
1.5
93.7
3.60
10.80
Y2
213.2
176.9
0.8
0.0
6.3
2.0
0.2
12.3
0.3
4.0
0.0
0.0
0.6
31.4
2798.4
0.0
1.0
0.0
1.0
0.6
0.0
0.0
0.0
0.3
0.3
2.3
3251.61
-
-
77
-------
TABLE 4. TEMPERATURE OF DEHYDRATION OF CaS03'0.5H20 IN DRIED
SCRUBBER SOLIDS
Sample
Analysis
3-20-76
4-03-76
4-14-76
4-21-76
5-01-76
5-08-76
5-15-76
5-21-76
5-31-76
6-09-76
6-20-76
6-21-76
6-23-76
6-25-76
6-27-76
7-01-76
7-03-76
7-07-76
7-09-76
7-11-76
7-12-76
7-15-76
7-17-76
Analysis
3-22-76
3-30-76
4-12-76
4-22-76
4-30-76
5-07-76
Temp. °
Point 1816
660
654
664
659
650
656
661
658
658
658
631
650
641
646
646
645
645
655
648
647
649
655
648
Point 2816
658
643
660
658
655
657
Std.
K Dev.a
(Venturi/ spray
4.0
2.3
2.5
7.3
1.2
0.0
1.5
2.3
1.5
0.6
0.6
1.5
1.7
1.4
0.8
1.5
5.9
2.1
1.5
14.2
1.5
1.7
2.6
(TCA)
1.0
3.4
0.6
1.0
3.5
0.6
Sample
tower)
7-20-76
7-22-76
7-24-76
7-26-76
7-30-76
8-01-76
8-07-76
8-09-76
8-11-76
8-17-76
8-20-76
8-22-76
8-25-76
8-26-76
8-27-76
8-28-76
8-29-76
8-30-76
9-05-76
9-10-76
9-16-76
9-23-76
9-28-76
5-14-76
5-22-76
6-01-76
6-10-76
6-19-76
Temp. °K
646
652
647
644
650
640
651
647
651
655
650
646
651
650
652
650
649
649
654
641
633
655
653
658
656
654
657
654
Std.
Dev.a
0.5
0.6
1.0
2.0
0.6
1.0
1.5
0.0
1.5
1.2
2.6
0.6
0.6
0.6
1.5
1.0
2.9
0.6
2.6
4.6
4.9
0.0
19.1
1.0
6.1
1.0
0.6
0.6
JStd. deviation calculated from 3 observations each sample.
78
-------
TABLE 5. ANALYTICAL RESULTS FOR GYPSUM DETERMINATION
BY DIFFERENTIAL SCANNING CALORIMETRY
Gypsum, % (wt)
Known Found
Std. dev.
Coeff. var.
10.00
7.00
4.00
1.000
0.600
0.500
0.300
0.100
9.82
6.90
3.94
0.982
0.585
0.490
0.314
0.109
0.30
0.30
0.18
0.046
0.028
0.022
0.015
0.007
3.05
4.34
4.57
4.68
4.79
4.49
4.78
6.42
TABLE 6. ANALYTICAL RESULTS FOR THE VENTURI/SPRAY TOWER SLUDGE DATA
Variable
Mean
Std. Dev.
Low
Values
High
Values
A. Lime Product Sludge (n = 66 data points)
ASH (wt. %) 31.5
CaO (wt. %) 29.3
S02 (wt. %) 24.9
S03 (wt. %) 7.1
C02 (wt. %) 1.5
Solids Recirculated (wt. %) 10.4
Oxidation (wt. %) 19.9
Settled Solids (wt. %) 43.4
Settled Bulk (g/cc) 1.3
19.11
8.66
14
,88
18
4.21
18.47
8.12
0.09
9.
4.
1,
12
21
15
2
1
6
10
35
1.2
50
38
34
12
2.7
15
90
52
1.4
B. Limestone Product Sludge (n = 98 data points)
ASH (wt. %) 32.5
CaO (wt. %) 29.7
S02 (wt. %) 21.1
S03 (wt. %) 6.0
C02 (wt. %) 5.5
Solids Recirculated (wt. %) 14.6
Oxidation (wt. %) 21.5
Settled Solids (wt. D 41.3
Settled Bulk (g/cc) 1.3
16.08
7.86
8.42
3.77
3.36
3.34
21.27
8.56
0.10
< 12
21
15
2
2
11
10
32
1.25
50
38
34
12
9
18
90
50
1.4
79
-------
TABLE 7. MEAN VALUES FOR HIGH SETTLED SOLIDS
Lime Limestone
Variable High Oxidation Other High Oxidation Other
ASH (wt. %)
CaO (wt. %)
S02 (wt. %)
C02 (wt. %)
Solids Recirculated (wt. %)
Oxidation (wt. %)
Settled Solids (wt. %)
Number of data pts.
55.7
15.6
0.5
0.3
18.6
96.6
65.0
2
33.0
28.9
25.8
6.0
12.9
15.4
55.1
5
64.5
10.3
0.2
0.7
16.4
98.3
63.3
6
38.6
27.4
18.2
6.7
17.7
17.9
53.2
5
TABLE 8. MEAN VALUES FOR LOW SETTLED SOLIDS
Variable Lime Limestone
ASH (wt. %) 17.0 14.0
CaO (wt. %) 37.5 38.8
S02 (wt. %) 25.2 27.2
C02 (wt. %) 2.8 7.2
Solids Recirculated (wt. %) 8.8 9.2
Oxidation (wt. %) 14.8 15.6
Settled Solids (wt. %) 26.9 26.9
Number of data pts. 6 11
80
-------
TABLE 9. MEAN VALUES FOR HIGH SETTLED BULK DENSITY
Lime
Limestone
Variable
High Oxidation Other High Oxidation Other
ASH (wt. %)
CaO (wt. %)
S02 (wt. %)
C02 (wt. %)
Solids Recirculated
Oxidation (wt. %)
Settled Bulk Density
Number of data pts .
(wt. %)
(g/cc)
55.7
15.6
0.5
0.3
18.6
96.6
1.65
2
34.3
28.8
25.2
3.2
7.6
11.4
1.43
4
64.5
12.0
0.2
0.7
16.4
98.3
1.61
6
32.4
30.5
24.1
4.8
15.2
11.4
1.43
4
TABLE 10. MEAN VALUES FOR LOW SETTLED BULK DENSITY
Variable
Lime
Limestone
ASH (wt. %)
CaO (wt. %)
S02 (wt. %)
C02 (wt. %)
Solids Recirculated (wt. %)
Oxidation (wt. %)
Settled Bulk Density (g/cc)
Number of data pts.
7.4
42.7
35.5
3.5
7.5
10.8
1.15
4
11.4
40.2
28.2
7.5
7.0
13.0
1.17
8
TABLE 11. PREDICTED RESPONSE FOR CHANGES IN VARIABLES-LIMESTONE SYSTEM
% Settled
Solids
41.8
38.8
35.6
43.8
62.5
24.3
Settled
Bulk Density
1.37
1.33
1.32
1.38
1.61
1.20
% Sulfite
Solids
15.0
34.0
21.0
21.0
0.4
37.0
% Solids
Recirculated
15.0
15.0
11.0
18.0
18.0
5.0
81
-------
TABLE 12. COEFFICIENTS AND STANDARD ERRORS FROM REGRESSION ANALYSIS
Dependent Variable
In (% settled solids)
In (% settled solids)
In (settled bulk
density)
In (settled bulk
density)
Sludge
Lime
Limestone
Lime
Limestone
In a
Coef./Std. Error
3.68/0232
2.84/0.133
0.40/0.062
0.14/0.040
bi
Coef./Std. Error
-0.09/0.032
-0.09/0.014
-0.05/0.009
-0.04/0.004
b2
Coef./Std Error
0.15/0.073
0.42/0.044
0.01/0.019
0.09/0.013
Model: InY = Ina +
b2lnX2
where Xj = % sulfite solids
X2 = % solids recirculated
TABLE 13. EVALUATION STATISTICS FROM REGRESSION ANALYSIS
Dependent Variable
Sludge
F (ni,n2)
s2
In (% settled solids)
In (% settled solids)
In (settled bulk
density)
In (settled bulk
density)
Lime 0.26 11.59 (2,63) 0.18 1.20
Limestone 0.63 80.51 (2,93) 0.12 1.13
Lime 0.47 28.11 (2,63) 0.05 1.05
Limestone 0.64 83.34 (2,93) 0.04 1.04
Multiple Correlation Coefficient'
2Standard Error of Estimate
82
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/7-80-100
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE ANDSUBTITLE
Processing Sludge: Sludge Characterization Studies
5. REPORT DATE
May 1980
6. PERFORMING ORGANIZATION CODE
. AUTHOR(S)
J.L.Crowe (TVA-Chattanooga) andS.K. Scale
(TVA-Muscle Shoals)
8. PERFORMING ORGANIZATION REPORT NO.
TVA EDT-109
J. PERFORMING ORGANIZATION NAME AND ADDRESS
Tennessee Valley Authority
Division of Energy Demonstrations and Technology
hattanooga, Tennessee 47401
1O. PROGRAM ELEMENT NO.
E HE 62 4 A
11. CONTRACT/GRANT NO.
EPA Inter agency Agreement
D5-0721
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 3/75-6/77
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES iERL_RTp project officer is Julian W. Jones, Mail Drop 61, 919/
541-2489. lERL-RTP's T.G. Brna is handling details of report completion.
16. ABSTRACT
The report gives results of slurry and solids characterization studies of
167 samples from the TVA/Shawnee turbulent contact absorber and venturi-spray
tower scrubbing systems. It summarizes the range of variability of solids and corre-
lation of this variability with plant operating conditions. It gives regression models
characterizing settled solids and bulk density as functions of calcium sulfite solids
and solids recirculated. Systems using limestone as absorbent precipitate CaSO3-
0. 5H2O primarily as single plates and relatively flat rosettes; spheroidal aggregates
of many small plate crystals result when lime is used. Sulfite crystal morphology
is independent of scrubber configuration. For limestone systems, crystal size is
clearly related to stoichiometric ratio (Ca:S); no such relationship is observed for
lime systems. Precipitation and crystal growth rates are believed responsible for
the difference in sulfite crystal morphology observed between the lime and limestone
systems. For forced oxidation with either absorbent, the reaction products have very
large, blocky CaSO4.2H2O crystals; no CaSO3-0. 5H2O forms are seen. The peak
area (thermal analysis) resulting from gypsum dehydration is linearly proportional
to gypsum concentration. A clear distinction between gypsum SO4(-2) and substituted
SO4(-2) in the sample is the basis for the CaSQ4-2H2O determination method used.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Pollution
Sludge
Analyzing
Properties
Gas Scrubbing
Calcium
Sulfites
Calcium Carbonates
Calcium Oxides
Gypsum
b. IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution Control
Stationary Sources
Characterization
Calcium Sulfites
13B
07A
14B
13H
07B
08G
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
91
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
83
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